private String calcSignature(final PsiType[] argTypes) {
    StringBuilder builder = new StringBuilder().append(myReferenceExpression.getReferenceName());
    builder.append("(");

    for (int i = 0; i < argTypes.length; i++) {
      PsiType type = argTypes[i];

      if (i > 0) {
        builder.append(", ");
      }
      if (type == null) {
        builder.append("Object");
      }
      else {
        builder.append(type.getPresentableText());
      }
    }
    builder.append(")");
    return builder.toString();
  }
private String calcSignature(final PsiType[] argTypes)