Code Inspection: Convert delegate variable to local function
Local functions, unlike lambdas or delegates, do not cause additional overhead because they are essentially regular methods. For example, instantiating and invoking a delegate requires additional members being generated by compiler and causing some memory overhead. Another benefit of local functions is their support for all the syntax elements allowed in regular methods. If it is possible to replace a delegate with local function, ReSharper suggests doing so.
Consider an example with a user-defined delegate. ReSharper replaces the delegate variable mymethod with a local function Mymethod. After the replacement, it also suggests removing the unused delegate MethodDelegate.