@Nullable
  public static PsiParameter getAnchorParameter(PsiParameterList parameterList, boolean isVarArgs) {
    final PsiParameter[] parameters = parameterList.getParameters();
    final int length = parameters.length;
    if (isVarArgs) {
      return length > 1 ? parameters[length - 2] : null;
    }
    else {
      return length > 0 ? parameters[length - 1] : null;
    }
  }
@Nullable
  public static PsiParameter getAnchorParameter(PsiParameterList parameterList, boolean isVarArgs)