public @NotNull PsiElement createColon() {
    final YAMLFile file = createDummyYamlWithText("? foo : bar");
    final PsiElement at = file.findElementAt("? foo ".length());
    assert at != null && at.getNode().getElementType() == YAMLTokenTypes.COLON;
    return at;
  }
public @NotNull PsiElement createColon()