A sidekick is a slang expression for a close companion or colleague (not necessarily in fiction) who is, or is generally regarded as, subordinate to the one he or she accompanies.
Simple Generic Repository abstraction to help us with Entity Framework Core
Extension methods enable you to "add" methods to existing types without creating a new derived type, recompiling, or otherwise modifying the original type. Extension methods are a special kind of static method, but they are called as if they were instance methods on the extended type. For client code written in C#, F# and Visual Basic, there is no apparent difference between calling an extension method and the methods that are actually defined in a type.
Simple Extension Methods project with some string, byte, enumerations and parse extensions.