Nullability (@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; }