boolean (PsiType one, PsiType two) { final PsiMethod method1 = LambdaUtil.getFunctionalInterfaceMethod(one); final PsiMethod method2 = LambdaUtil.getFunctionalInterfaceMethod(two); if (method1 == null || method2 == null) { return false; } final PsiType returnType1 = method1.getReturnType(); final PsiType returnType2 = method2.getReturnType(); if (PsiTypes.voidType().equals(returnType1) ^ PsiTypes.voidType().equals(returnType2)) { return false; } return method1.getParameterList().getParametersCount() == method2.getParameterList().getParametersCount(); }