public static Builder builder(final SqlStruct schema) {
    return new Builder(schema);
  }
@Test
  public void shouldImplementHashCodeAndEquals() {
    new EqualsTester()
        .addEqualityGroup(
            KsqlStruct.builder(SCHEMA).build(),
            KsqlStruct.builder(SCHEMA).build(),
            KsqlStruct.builder(SCHEMA).set(0, (Object) null).build(),
            KsqlStruct.builder(SCHEMA).set(0, Optional.empty()).build()
        )
        .addEqualityGroup(
            KsqlStruct.builder(SCHEMA).set(1, true).build(),
            KsqlStruct.builder(SCHEMA).set(1, Optional.of(true)).build()
        )
        .addEqualityGroup(
            KsqlStruct.builder(SqlTypes.struct().build())
        )
        .testEquals();
  }