@Nullable
  private static PsiVariable getFromAssignment(final PsiAssignmentExpression assignment) {
    final PsiExpression reference = assignment.getLExpression();
    final PsiElement referencedElement = reference instanceof PsiReferenceExpression ? ((PsiReferenceExpression)reference).resolve() : null;
    return referencedElement instanceof PsiVariable ? (PsiVariable)referencedElement : null;
  }
@Nullable
  private static PsiVariable getFromAssignment(final PsiAssignmentExpression assignment)