ExecFunc implements context for a function which has no return values and executes that function.

ExecFuncWithThreeReturns wraps a function which has three return values given that last one is error and executes that function in a goroutine there by implementing context if context is cancelled before function returns it will return context error otherwise it will return function's return values.

ExecFuncWithTwoReturns wraps a function which has two return values given that last one is error and executes that function in a goroutine there by implementing context if context is cancelled before function returns it will return context error otherwise it will return function's return values.

ValueOrDefault returns default context if given is nil (using interface to avoid static check reporting).

WithValues combines multiple key-value into an existing context.