List<PsiMember> (@Nullable List<? extends PsiElementClassMember> classMemberList) { if (classMemberList == null || classMemberList.isEmpty()) { return Collections.emptyList(); } List<PsiMember> psiMemberList = new ArrayList<>(); for (PsiElementClassMember classMember : classMemberList) { psiMemberList.add(classMember.getElement()); } return psiMemberList; }