public static MutationSignature getHardcodedMutation(PsiMethod method) {
    PsiClass aClass = method.getContainingClass();
    if (aClass == null) return MutationSignature.unknown();
    String className = aClass.getQualifiedName();
    if (className == null) return MutationSignature.unknown();
    String name = method.getName();

    if ("java.util.Objects".equals(className) && "requireNonNull".equals(name)) {
      PsiParameter[] parameters = method.getParameterList().getParameters();
      if (parameters.length == 2 && parameters[1].getType().getCanonicalText().contains("Supplier")) {
        return MutationSignature.unknown();
      }
    }

    if ("remove".equals(name) || "add".equals(name)) {
      return MutationSignature.pure().alsoMutatesThis();
    }

    if ("java.lang.System".equals(className)) {
      return MutationSignature.unknown();
    }
    if (JAVA_UTIL_ARRAYS.equals(className)) {
      return PURE_ARRAY_METHODS.contains(name) ? MutationSignature.pure() :
             // else: fill, parallelPrefix, parallelSort, sort
             MutationSignature.pure().alsoMutatesArg(0);
    }
    if (QUEUE_POLL.methodMatches(method)) {
      return MutationSignature.pure().alsoMutatesThis();
    }
    return MutationSignature.pure();
  }
public static MutationSignature getHardcodedMutation(PsiMethod method)