PsiType (PsiMethodCallExpression call) { JavaResolveResult resolveResult = call.resolveMethodGenerics(); PsiMethod method = call.resolveMethod(); if(method == null) return null; PsiParameter[] parameters = method.getParameterList().getParameters(); if(parameters.length != 1) return null; return resolveResult.getSubstitutor().substitute(parameters[0].getType()); }