Add ability to get subschemas of CombinedSchema in insertion order

core/src/main/java/org/everit/json/schema/CombinedSchema.java

@@ -154,6 +154,8 @@ public static Builder oneOf(Collection<Schema> schemas) {
 
     private final boolean synthetic;
 
+    private final Collection<Schema> orderedSubschemas;
+
     private final Collection<Schema> subschemas;
 
     private final ValidationCriterion criterion;
@@ -168,6 +170,7 @@ public CombinedSchema(Builder builder) {
         super(builder);
         this.synthetic = builder.synthetic;
         this.criterion = requireNonNull(builder.criterion, "criterion cannot be null");
+        this.orderedSubschemas = builder.subschemas;
         this.subschemas = sortByCombinedFirst(requireNonNull(builder.subschemas, "subschemas cannot be null"));
     }
 
@@ -191,6 +194,14 @@ public ValidationCriterion getCriterion() {
         return criterion;
     }
 
+    /**
+     * Returns the subschemas in the order they were added.
+     * @return the subschemas in insertion order
+     */
+    public Collection<Schema> getOrderedSubschemas() {
+        return orderedSubschemas;
+    }
+
     public Collection<Schema> getSubschemas() {
         return subschemas;
     }

core/src/test/java/org/everit/json/schema/CombinedSchemaTest.java

@@ -79,6 +79,18 @@ public void subschemasSort() {
         assertEquals(booleanSchema2, subschemas[5]);
         assertEquals(emptySchema2, subschemas[6]);
         assertEquals(nullSchema2, subschemas[7]);
+
+        subschemas = subject.getOrderedSubschemas().toArray();
+
+        assertEquals(8, subschemas.length);
+        assertEquals(nullSchema1, subschemas[0]);
+        assertEquals(emptySchema1, subschemas[1]);
+        assertEquals(booleanSchema1, subschemas[2]);
+        assertEquals(subcombined1, subschemas[3]);
+        assertEquals(booleanSchema2, subschemas[4]);
+        assertEquals(emptySchema2, subschemas[5]);
+        assertEquals(nullSchema2, subschemas[6]);
+        assertEquals(subcombined2, subschemas[7]);
     }
 
     @Test
@@ -172,7 +184,7 @@ public void reportCauses() {
     public void equalsVerifier() {
         EqualsVerifier.forClass(CombinedSchema.class)
                 .withRedefinedSuperclass()
-                .withIgnoredFields("schemaLocation", "location")
+                .withIgnoredFields("schemaLocation", "location", "orderedSubschemas")
                 .suppress(Warning.STRICT_INHERITANCE)
                 .verify();
     }