static Result coerceUserList(
      final Collection<Expression> expressions,
      final ExpressionTypeManager typeManager
  ) {
    return coerceUserList(expressions, typeManager, Collections.emptyMap());
  }
@Test
  public void shouldHandleOnlyNulls() {
    // Given:
    final ImmutableList<Expression> expressions = ImmutableList.of(
        new NullLiteral(),
        new NullLiteral()
    );

    // When:
    final Result result = CoercionUtil.coerceUserList(expressions, typeManager);

    // Then:
    assertThat(result.commonType(), is(Optional.empty()));
    assertThat(result.expressions(), is(ImmutableList.of(
        new NullLiteral(),
        new NullLiteral()
    )));
  }