Allow nullable subfields for OneOfType (#36297)

Author: baeminbo

sdks/java/core/src/main/java/org/apache/beam/sdk/schemas/logicaltypes/OneOfType.java

@@ -74,9 +74,6 @@ public static OneOfType create(Field... fields) {
 
   /** Create an {@link OneOfType} logical type. */
   public static OneOfType create(List<Field> fields) {
-    for (Field f : fields) {
-      checkArgument(!f.getType().getNullable(), "OneOf fields do not support nullable subfields.");
-    }
     return new OneOfType(fields);
   }
 

sdks/java/core/src/test/java/org/apache/beam/sdk/schemas/logicaltypes/LogicalTypesTest.java

@@ -17,7 +17,6 @@
  */
 package org.apache.beam.sdk.schemas.logicaltypes;
 
-import static org.hamcrest.MatcherAssert.assertThat;
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertThrows;
@@ -33,7 +32,6 @@
 import org.apache.beam.sdk.schemas.logicaltypes.OneOfType.Value;
 import org.apache.beam.sdk.values.Row;
 import org.apache.beam.vendor.guava.v32_1_2_jre.com.google.common.collect.ImmutableMap;
-import org.hamcrest.Matchers;
 import org.junit.Test;
 
 /** Unit tests for logical types. */
@@ -90,21 +88,6 @@ public void testOneOf() {
     assertEquals(stringOneOf, stringOneOf2);
   }
 
-  @Test
-  public void testOneOfNullable() {
-    Exception exception =
-        assertThrows(
-            IllegalArgumentException.class,
-            () -> {
-              OneOfType.create(
-                  Field.nullable("string", FieldType.STRING), Field.of("int32", FieldType.INT32));
-            });
-
-    assertThat(
-        exception.getMessage(),
-        Matchers.containsString("OneOf fields do not support nullable subfields."));
-  }
-
   @Test
   public void testNanosInstant() {
     Schema rowSchema = new NanosInstant().getBaseType().getRowSchema();