@NotNull
  private static Nullability getLambdaParameterNullability(@NotNull PsiMethod method, int parameterIndex, int lambdaParameterIndex) {
    if (OPTIONAL_FUNCTIONS.methodMatches(method)) {
      if (parameterIndex == 0 && lambdaParameterIndex == 0) {
        return Nullability.NOT_NULL;
      }
    }
    else if (MAP_COMPUTE.methodMatches(method)) {
      if (parameterIndex == 1 && lambdaParameterIndex == 1) {
        return Nullability.NULLABLE;
      }
    }
    return Nullability.UNKNOWN;
  }
@NotNull
  private static Nullability getLambdaParameterNullability(@NotNull PsiMethod method, int parameterIndex, int lambdaParameterIndex)