public DropSourceCommand create(final DropStream statement) {
    return create(
        statement.getName(),
        statement.getIfExists(),
        statement.isDeleteTopic(),
        DataSourceType.KSTREAM
    );
  }
@Test
  public void shouldFailDropSourceOnMissingSourceWithNoIfExistsForStream() {
    // Given:
    final DropStream dropStream = new DropStream(SOME_NAME, false, true);
    when(metaStore.getSource(SOME_NAME)).thenReturn(null);

    // When:
    final Exception e = assertThrows(
        KsqlException.class,
        () -> dropSourceFactory.create(dropStream)
    );

    // Then:
    assertThat(e.getMessage(), containsString("Stream bob does not exist."));
  }