public static boolean isKeyOfMap(GrReferenceExpression ref) {
    if (!(ref.getParent() instanceof GrIndexProperty) && org.jetbrains.plugins.groovy.lang.psi.util.PsiUtil.isCall(ref)) return false;
    // TODO separate element for spread expression
    if (ref.getDotTokenType() == GroovyTokenTypes.mSPREAD_DOT) return false;
    return ref.resolve() instanceof GroovyMapProperty;
  }
public static boolean isKeyOfMap(GrReferenceExpression ref)