@@ -28,12 +28,14 @@
 import java.util.Map;
 import java.util.Set;
 import java.util.function.Consumer;
-import java.util.stream.Collectors;
 
 import static graphql.Assert.assertNotNull;
 import static graphql.Assert.assertTrue;
 import static graphql.schema.GraphQLTypeUtil.simplePrint;
 import static graphql.schema.GraphQLTypeUtil.unwrapAll;
+import static java.util.stream.Collectors.joining;
+import static java.util.stream.Collectors.toList;
+import static java.util.stream.Collectors.toSet;
 
 /**
  * Intentionally Mutable
@@ -193,7 +195,7 @@ public boolean hasChildren() {
 
     public GraphQLOutputType getType(GraphQLSchema schema) {
         List<GraphQLFieldDefinition> fieldDefinitions = getFieldDefinitions(schema);
-        Set<String> fieldTypes = fieldDefinitions.stream().map(fd -> simplePrint(fd.getType())).collect(Collectors.toSet());
+        Set<String> fieldTypes = fieldDefinitions.stream().map(fd -> simplePrint(fd.getType())).collect(toSet());
         Assert.assertTrue(fieldTypes.size() == 1, () -> "More than one type ... use getTypes");
         return fieldDefinitions.get(0).getType();
     }
@@ -355,6 +357,29 @@ public List<ExecutableNormalizedField> getChildrenWithSameResultKey(String resul
         return FpKit.filterList(children, child -> child.getResultKey().equals(resultKey));
     }
 
+    public List<ExecutableNormalizedField> getChildren(int includingRelativeLevel) {
+        List<ExecutableNormalizedField> result = new ArrayList<>();
+        assertTrue(includingRelativeLevel >= 1, () -> "relative level must be >= 1");
+
+        this.getChildren().forEach(child -> {
+            traverseImpl(child, result::add, 1, includingRelativeLevel);
+        });
+        return result;
+    }
+
+    /**
+     * This returns the child fields that can be used if the object is of the specified object type
+     *
+     * @param objectTypeName the object type
+     *
+     * @return a list of child fields that would apply to that object type
+     */
+    public List<ExecutableNormalizedField> getChildren(String objectTypeName) {
+        return children.stream()
+                .filter(cld -> cld.objectTypeNames.contains(objectTypeName))
+                .collect(toList());
+    }
+
     public int getLevel() {
         return level;
     }
@@ -374,19 +399,10 @@ public String toString() {
                 objectTypeNamesToString() + "." + fieldName +
                 ", alias=" + alias +
                 ", level=" + level +
-                ", children=" + children.stream().map(ExecutableNormalizedField::toString).collect(Collectors.joining("\n")) +
+                ", children=" + children.stream().map(ExecutableNormalizedField::toString).collect(joining("\n")) +
                 '}';
     }
 
-    public List<ExecutableNormalizedField> getChildren(int includingRelativeLevel) {
-        List<ExecutableNormalizedField> result = new ArrayList<>();
-        assertTrue(includingRelativeLevel >= 1, () -> "relative level must be >= 1");
-
-        this.getChildren().forEach(child -> {
-            traverseImpl(child, result::add, 1, includingRelativeLevel);
-        });
-        return result;
-    }
 
     public void traverseSubTree(Consumer<ExecutableNormalizedField> consumer) {
         this.getChildren().forEach(child -> {
 
@@ -0,0 +1,63 @@
+package graphql.normalized
+
+import graphql.TestUtil
+import graphql.execution.CoercedVariables
+import graphql.language.Document
+import graphql.schema.GraphQLSchema
+import spock.lang.Specification
+
+class ExecutableNormalizedFieldTest extends Specification {
+
+    def "can get children of object type"() {
+
+        String schema = """
+        type Query{ 
+            pets: [Pet]
+        }
+        interface Pet {
+            id: ID
+            name : String!
+        }
+        type Cat implements Pet{
+            id: ID
+            name : String!
+            meow : String
+        }
+        type Dog implements Pet{
+            id: ID
+            name : String!
+            woof : String
+        }
+        """
+        GraphQLSchema graphQLSchema = TestUtil.schema(schema)
+
+        String query = """
+        {
+            pets {
+                id
+                name
+                ... on Dog {
+                    woof
+                }
+                ... on Cat {
+                    meow
+                }     
+            }
+        }
+        
+        """
+        Document document = TestUtil.parseQuery(query)
+
+        ExecutableNormalizedOperationFactory normalizedOperationFactory = new ExecutableNormalizedOperationFactory()
+        def normalizedOperation = normalizedOperationFactory.createExecutableNormalizedOperation(graphQLSchema, document, null, CoercedVariables.emptyVariables())
+
+        def pets = normalizedOperation.getTopLevelFields()[0]
+        def allChildren = pets.getChildren()
+        def dogFields = pets.getChildren("Dog")
+
+        expect:
+        allChildren.collect { it.name } == ["id", "name", "woof", "meow"]
+        dogFields.collect { it.name } == ["id", "name", "woof"]
+    }
+
+}