diff --git a/core/src/main/kotlin/net/corda/core/contracts/Amount.kt b/core/src/main/kotlin/net/corda/core/contracts/Amount.kt
index e8d3982c2f..e08ddce671 100644
--- a/core/src/main/kotlin/net/corda/core/contracts/Amount.kt
+++ b/core/src/main/kotlin/net/corda/core/contracts/Amount.kt
@@ -391,10 +391,10 @@ class AmountTransfer<T : Any, P : Any>(val quantityDelta: Long,
      * relative asset exchange happens, but with each party exchanging versus a central counterparty, or clearing house.
      *
      * @param centralParty The central party to face the exchange against.
-     * @return Returns two new AmountTransfers each between one of the original parties and the centralParty.
+     * @return Returns a list of two new AmountTransfers each between one of the original parties and the centralParty.
      * The net total exchange is the same as in the original input.
      */
-    fun novate(centralParty: P): Pair<AmountTransfer<T, P>, AmountTransfer<T, P>> = Pair(copy(destination = centralParty), copy(source = centralParty))
+    fun novate(centralParty: P): List<AmountTransfer<T, P>> = listOf(copy(destination = centralParty), copy(source = centralParty))
 
     /**
      * Applies this AmountTransfer to a list of [SourceAndAmount] objects representing balances.
diff --git a/core/src/main/kotlin/net/corda/core/contracts/Structures.kt b/core/src/main/kotlin/net/corda/core/contracts/Structures.kt
index 437de33344..370e3bd06a 100644
--- a/core/src/main/kotlin/net/corda/core/contracts/Structures.kt
+++ b/core/src/main/kotlin/net/corda/core/contracts/Structures.kt
@@ -147,6 +147,12 @@ data class Issued<out P : Any>(val issuer: PartyAndReference, val product: P) {
 fun <T : Any> Amount<Issued<T>>.withoutIssuer(): Amount<T> = Amount(quantity, token.product)
 
 // DOCSTART 3
+
+/**
+ * Return structure for [OwnableState.withNewOwner]
+ */
+data class CommandAndState(val command: CommandData, val ownableState: OwnableState)
+
 /**
  * A contract state that can have a single owner.
  */
@@ -155,7 +161,7 @@ interface OwnableState : ContractState {
     val owner: AbstractParty
 
     /** Copies the underlying data structure, replacing the owner field with this new value and leaving the rest alone */
-    fun withNewOwner(newOwner: AbstractParty): Pair<CommandData, OwnableState>
+    fun withNewOwner(newOwner: AbstractParty): CommandAndState
 }
 // DOCEND 3
 
diff --git a/core/src/main/kotlin/net/corda/core/node/PhysicalLocationStructures.kt b/core/src/main/kotlin/net/corda/core/node/PhysicalLocationStructures.kt
index 049845432f..754fbbc44e 100644
--- a/core/src/main/kotlin/net/corda/core/node/PhysicalLocationStructures.kt
+++ b/core/src/main/kotlin/net/corda/core/node/PhysicalLocationStructures.kt
@@ -3,6 +3,8 @@ package net.corda.core.node
 import net.corda.core.serialization.CordaSerializable
 import java.util.*
 
+data class ScreenCoordinate(val screenX: Double, val screenY: Double)
+
 /** A latitude/longitude pair. */
 @CordaSerializable
 data class WorldCoordinate(val latitude: Double, val longitude: Double) {
@@ -21,7 +23,7 @@ data class WorldCoordinate(val latitude: Double, val longitude: Double) {
      */
     @Suppress("unused") // Used from the visualiser GUI.
     fun project(screenWidth: Double, screenHeight: Double, topLatitude: Double, bottomLatitude: Double,
-                leftLongitude: Double, rightLongitude: Double): Pair<Double, Double> {
+                leftLongitude: Double, rightLongitude: Double): ScreenCoordinate {
         require(latitude in bottomLatitude..topLatitude)
         require(longitude in leftLongitude..rightLongitude)
 
@@ -33,7 +35,7 @@ data class WorldCoordinate(val latitude: Double, val longitude: Double) {
         val topLatRel = screenYRelative(topLatitude)
         val bottomLatRel = screenYRelative(bottomLatitude)
         fun latitudeToScreenY(lat: Double) = screenHeight * (screenYRelative(lat) - topLatRel) / (bottomLatRel - topLatRel)
-        return Pair(longitudeToScreenX(longitude), latitudeToScreenY(latitude))
+        return ScreenCoordinate(longitudeToScreenX(longitude), latitudeToScreenY(latitude))
     }
 }
 
diff --git a/core/src/test/kotlin/net/corda/core/flows/ContractUpgradeFlowTest.kt b/core/src/test/kotlin/net/corda/core/flows/ContractUpgradeFlowTest.kt
index 9f21d4d944..bc05d5be77 100644
--- a/core/src/test/kotlin/net/corda/core/flows/ContractUpgradeFlowTest.kt
+++ b/core/src/test/kotlin/net/corda/core/flows/ContractUpgradeFlowTest.kt
@@ -202,7 +202,7 @@ class ContractUpgradeFlowTest {
 
             override fun move(newAmount: Amount<Issued<Currency>>, newOwner: AbstractParty) = copy(amount = amount.copy(newAmount.quantity), owners = listOf(newOwner))
             override fun toString() = "${Emoji.bagOfCash}New Cash($amount at ${amount.token.issuer} owned by $owner)"
-            override fun withNewOwner(newOwner: AbstractParty) = Pair(Cash.Commands.Move(), copy(owners = listOf(newOwner)))
+            override fun withNewOwner(newOwner: AbstractParty) = CommandAndState(Cash.Commands.Move(), copy(owners = listOf(newOwner)))
         }
 
         override fun upgrade(state: Cash.State) = CashV2.State(state.amount.times(1000), listOf(state.owner))
diff --git a/core/src/test/kotlin/net/corda/core/serialization/TransactionSerializationTests.kt b/core/src/test/kotlin/net/corda/core/serialization/TransactionSerializationTests.kt
index 88e2eecfc2..492b50826f 100644
--- a/core/src/test/kotlin/net/corda/core/serialization/TransactionSerializationTests.kt
+++ b/core/src/test/kotlin/net/corda/core/serialization/TransactionSerializationTests.kt
@@ -32,7 +32,7 @@ class TransactionSerializationTests : TestDependencyInjectionBase() {
             override val participants: List<AbstractParty>
                 get() = listOf(owner)
 
-            override fun withNewOwner(newOwner: AbstractParty) = Pair(Commands.Move(), copy(owner = newOwner))
+            override fun withNewOwner(newOwner: AbstractParty) = CommandAndState(Commands.Move(), copy(owner = newOwner))
         }
 
         interface Commands : CommandData {
diff --git a/finance/src/main/java/net/corda/contracts/JavaCommercialPaper.java b/finance/src/main/java/net/corda/contracts/JavaCommercialPaper.java
index 3472b8bd2c..e51d3889fe 100644
--- a/finance/src/main/java/net/corda/contracts/JavaCommercialPaper.java
+++ b/finance/src/main/java/net/corda/contracts/JavaCommercialPaper.java
@@ -68,8 +68,8 @@ public class JavaCommercialPaper implements Contract {
 
         @NotNull
         @Override
-        public Pair<CommandData, OwnableState> withNewOwner(@NotNull AbstractParty newOwner) {
-            return new Pair<>(new Commands.Move(), new State(this.issuance, newOwner, this.faceValue, this.maturityDate));
+        public CommandAndState withNewOwner(@NotNull AbstractParty newOwner) {
+            return new CommandAndState(new Commands.Move(), new State(this.issuance, newOwner, this.faceValue, this.maturityDate));
         }
 
         public ICommercialPaperState withFaceValue(Amount<Issued<Currency>> newFaceValue) {
diff --git a/finance/src/main/kotlin/net/corda/contracts/CommercialPaper.kt b/finance/src/main/kotlin/net/corda/contracts/CommercialPaper.kt
index 70b795a934..eb22a8a58f 100644
--- a/finance/src/main/kotlin/net/corda/contracts/CommercialPaper.kt
+++ b/finance/src/main/kotlin/net/corda/contracts/CommercialPaper.kt
@@ -73,7 +73,7 @@ class CommercialPaper : Contract {
         val token: Issued<Terms>
             get() = Issued(issuance, Terms(faceValue.token, maturityDate))
 
-        override fun withNewOwner(newOwner: AbstractParty) = Pair(Commands.Move(), copy(owner = newOwner))
+        override fun withNewOwner(newOwner: AbstractParty) = CommandAndState(Commands.Move(), copy(owner = newOwner))
         override fun toString() = "${Emoji.newspaper}CommercialPaper(of $faceValue redeemable on $maturityDate by '$issuance', owned by $owner)"
 
         // Although kotlin is smart enough not to need these, as we are using the ICommercialPaperState, we need to declare them explicitly for use later,
diff --git a/finance/src/main/kotlin/net/corda/contracts/CommercialPaperLegacy.kt b/finance/src/main/kotlin/net/corda/contracts/CommercialPaperLegacy.kt
index b53246d25b..b7086a6a29 100644
--- a/finance/src/main/kotlin/net/corda/contracts/CommercialPaperLegacy.kt
+++ b/finance/src/main/kotlin/net/corda/contracts/CommercialPaperLegacy.kt
@@ -36,7 +36,7 @@ class CommercialPaperLegacy : Contract {
         override val participants = listOf(owner)
 
         fun withoutOwner() = copy(owner = NULL_PARTY)
-        override fun withNewOwner(newOwner: AbstractParty) = Pair(Commands.Move(), copy(owner = newOwner))
+        override fun withNewOwner(newOwner: AbstractParty) = CommandAndState(Commands.Move(), copy(owner = newOwner))
         override fun toString() = "${Emoji.newspaper}CommercialPaper(of $faceValue redeemable on $maturityDate by '$issuance', owned by $owner)"
 
         // Although kotlin is smart enough not to need these, as we are using the ICommercialPaperState, we need to declare them explicitly for use later,
diff --git a/finance/src/main/kotlin/net/corda/contracts/asset/Cash.kt b/finance/src/main/kotlin/net/corda/contracts/asset/Cash.kt
index 9b0ca94da2..5e51024f9a 100644
--- a/finance/src/main/kotlin/net/corda/contracts/asset/Cash.kt
+++ b/finance/src/main/kotlin/net/corda/contracts/asset/Cash.kt
@@ -108,7 +108,7 @@ class Cash : OnLedgerAsset<Currency, Cash.Commands, Cash.State>() {
 
         override fun toString() = "${Emoji.bagOfCash}Cash($amount at ${amount.token.issuer} owned by $owner)"
 
-        override fun withNewOwner(newOwner: AbstractParty) = Pair(Commands.Move(), copy(owner = newOwner))
+        override fun withNewOwner(newOwner: AbstractParty) = CommandAndState(Commands.Move(), copy(owner = newOwner))
 
         /** Object Relational Mapping support. */
         override fun generateMappedObject(schema: MappedSchema): PersistentState {
diff --git a/finance/src/main/kotlin/net/corda/contracts/asset/CommodityContract.kt b/finance/src/main/kotlin/net/corda/contracts/asset/CommodityContract.kt
index e6697f2564..cf36ea7d7b 100644
--- a/finance/src/main/kotlin/net/corda/contracts/asset/CommodityContract.kt
+++ b/finance/src/main/kotlin/net/corda/contracts/asset/CommodityContract.kt
@@ -110,7 +110,7 @@ class CommodityContract : OnLedgerAsset<Commodity, CommodityContract.Commands, C
 
         override fun toString() = "Commodity($amount at ${amount.token.issuer} owned by $owner)"
 
-        override fun withNewOwner(newOwner: AbstractParty) = Pair(Commands.Move(), copy(owner = newOwner))
+        override fun withNewOwner(newOwner: AbstractParty) = CommandAndState(Commands.Move(), copy(owner = newOwner))
     }
 
     // Just for grouping
diff --git a/finance/src/main/kotlin/net/corda/contracts/asset/Obligation.kt b/finance/src/main/kotlin/net/corda/contracts/asset/Obligation.kt
index 7fef1625ea..218d2dab23 100644
--- a/finance/src/main/kotlin/net/corda/contracts/asset/Obligation.kt
+++ b/finance/src/main/kotlin/net/corda/contracts/asset/Obligation.kt
@@ -333,7 +333,7 @@ class Obligation<P : Any> : Contract {
             }
         }
 
-        override fun withNewOwner(newOwner: AbstractParty) = Pair(Commands.Move(), copy(beneficiary = newOwner))
+        override fun withNewOwner(newOwner: AbstractParty) = CommandAndState(Commands.Move(), copy(beneficiary = newOwner))
     }
 
     // Just for grouping
diff --git a/finance/src/test/kotlin/net/corda/contracts/DummyFungibleContract.kt b/finance/src/test/kotlin/net/corda/contracts/DummyFungibleContract.kt
index e01f13618f..f8d78a6852 100644
--- a/finance/src/test/kotlin/net/corda/contracts/DummyFungibleContract.kt
+++ b/finance/src/test/kotlin/net/corda/contracts/DummyFungibleContract.kt
@@ -71,7 +71,7 @@ class DummyFungibleContract : OnLedgerAsset<Currency, DummyFungibleContract.Comm
 
         override fun toString() = "${Emoji.bagOfCash}Cash($amount at ${amount.token.issuer} owned by $owner)"
 
-        override fun withNewOwner(newOwner: AbstractParty) = Pair(Commands.Move(), copy(owner = newOwner))
+        override fun withNewOwner(newOwner: AbstractParty) = CommandAndState(Commands.Move(), copy(owner = newOwner))
 
         /** Object Relational Mapping support. */
         override fun generateMappedObject(schema: MappedSchema): PersistentState {
diff --git a/node-schemas/src/test/kotlin/net/corda/node/services/vault/schemas/VaultSchemaTest.kt b/node-schemas/src/test/kotlin/net/corda/node/services/vault/schemas/VaultSchemaTest.kt
index c6a6cfb9dd..554353c29e 100644
--- a/node-schemas/src/test/kotlin/net/corda/node/services/vault/schemas/VaultSchemaTest.kt
+++ b/node-schemas/src/test/kotlin/net/corda/node/services/vault/schemas/VaultSchemaTest.kt
@@ -87,7 +87,7 @@ class VaultSchemaTest : TestDependencyInjectionBase() {
             override val participants: List<AbstractParty>
                 get() = listOf(owner)
 
-            override fun withNewOwner(newOwner: AbstractParty) = Pair(Commands.Create(), copy(owner = newOwner))
+            override fun withNewOwner(newOwner: AbstractParty) = CommandAndState(Commands.Create(), copy(owner = newOwner))
         }
 
         interface Commands : CommandData {
diff --git a/samples/network-visualiser/src/main/kotlin/net/corda/netmap/VisualiserViewModel.kt b/samples/network-visualiser/src/main/kotlin/net/corda/netmap/VisualiserViewModel.kt
index 0b34998c98..547d29be7b 100644
--- a/samples/network-visualiser/src/main/kotlin/net/corda/netmap/VisualiserViewModel.kt
+++ b/samples/network-visualiser/src/main/kotlin/net/corda/netmap/VisualiserViewModel.kt
@@ -8,6 +8,7 @@ import javafx.scene.shape.Circle
 import javafx.scene.shape.Line
 import javafx.util.Duration
 import net.corda.core.crypto.commonName
+import net.corda.core.node.ScreenCoordinate
 import net.corda.core.utilities.ProgressTracker
 import net.corda.netmap.simulation.IRSSimulation
 import net.corda.testing.node.MockNetwork
@@ -26,7 +27,7 @@ class VisualiserViewModel {
     inner class NodeWidget(val node: MockNetwork.MockNode, val innerDot: Circle, val outerDot: Circle, val longPulseDot: Circle,
                            val pulseAnim: Animation, val longPulseAnim: Animation,
                            val nameLabel: Label, val statusLabel: Label) {
-        fun position(nodeCoords: (node: MockNetwork.MockNode) -> Pair<Double, Double>) {
+        fun position(nodeCoords: (node: MockNetwork.MockNode) -> ScreenCoordinate) {
             val (x, y) = nodeCoords(node)
             innerDot.centerX = x
             innerDot.centerY = y
@@ -76,7 +77,7 @@ class VisualiserViewModel {
         }
     }
 
-    fun nodeMapCoords(node: MockNetwork.MockNode): Pair<Double, Double> {
+    fun nodeMapCoords(node: MockNetwork.MockNode): ScreenCoordinate {
         // For an image of the whole world, we use:
         // return node.place.coordinate.project(mapImage.fitWidth, mapImage.fitHeight, 85.0511, -85.0511, -180.0, 180.0)
 
@@ -90,7 +91,7 @@ class VisualiserViewModel {
         }
     }
 
-    fun nodeCircleCoords(type: NetworkMapVisualiser.NodeType, index: Int): Pair<Double, Double> {
+    fun nodeCircleCoords(type: NetworkMapVisualiser.NodeType, index: Int): ScreenCoordinate {
         val stepRad: Double = when (type) {
             NetworkMapVisualiser.NodeType.BANK -> 2 * Math.PI / bankCount
             NetworkMapVisualiser.NodeType.SERVICE -> (2 * Math.PI / serviceCount)
@@ -109,7 +110,7 @@ class VisualiserViewModel {
         val circleY = view.stageHeight / 2 + yOffset
         val x: Double = radius * Math.cos(tangentRad) + circleX
         val y: Double = radius * Math.sin(tangentRad) + circleY
-        return Pair(x, y)
+        return ScreenCoordinate(x, y)
     }
 
     fun createNodes() {
diff --git a/test-utils/src/main/kotlin/net/corda/testing/contracts/DummyContract.kt b/test-utils/src/main/kotlin/net/corda/testing/contracts/DummyContract.kt
index bf13dab4f3..92fb2c1084 100644
--- a/test-utils/src/main/kotlin/net/corda/testing/contracts/DummyContract.kt
+++ b/test-utils/src/main/kotlin/net/corda/testing/contracts/DummyContract.kt
@@ -21,7 +21,7 @@ data class DummyContract(override val legalContractReference: SecureHash = Secur
         override val participants: List<AbstractParty>
             get() = listOf(owner)
 
-        override fun withNewOwner(newOwner: AbstractParty) = Pair(Commands.Move(), copy(owner = newOwner))
+        override fun withNewOwner(newOwner: AbstractParty) = CommandAndState(Commands.Move(), copy(owner = newOwner))
     }
 
     /**
diff --git a/tools/explorer/src/main/kotlin/net/corda/explorer/views/Network.kt b/tools/explorer/src/main/kotlin/net/corda/explorer/views/Network.kt
index 02cf2bd93b..9df6973b25 100644
--- a/tools/explorer/src/main/kotlin/net/corda/explorer/views/Network.kt
+++ b/tools/explorer/src/main/kotlin/net/corda/explorer/views/Network.kt
@@ -30,6 +30,7 @@ import net.corda.core.contracts.ContractState
 import net.corda.core.crypto.toBase58String
 import net.corda.core.identity.Party
 import net.corda.core.node.NodeInfo
+import net.corda.core.node.ScreenCoordinate
 import net.corda.explorer.formatters.PartyNameFormatter
 import net.corda.explorer.model.CordaView
 import tornadofx.*
@@ -122,11 +123,11 @@ class Network : CordaView() {
             contentDisplay = ContentDisplay.TOP
             val coordinate = Bindings.createObjectBinding({
                 // These coordinates are obtained when we generate the map using TileMill.
-                node.worldMapLocation?.coordinate?.project(mapPane.width, mapPane.height, 85.0511, -85.0511, -180.0, 180.0) ?: Pair(0.0, 0.0)
+                node.worldMapLocation?.coordinate?.project(mapPane.width, mapPane.height, 85.0511, -85.0511, -180.0, 180.0) ?: ScreenCoordinate(0.0, 0.0)
             }, arrayOf(mapPane.widthProperty(), mapPane.heightProperty()))
             // Center point of the label.
-            layoutXProperty().bind(coordinate.map { it.first - width / 2 })
-            layoutYProperty().bind(coordinate.map { it.second - height / 4 })
+            layoutXProperty().bind(coordinate.map { it.screenX - width / 2 })
+            layoutYProperty().bind(coordinate.map { it.screenY - height / 4 })
         }
 
         val button = node.renderButton(mapLabel)