kubernetes/vendor/golang.org/x/tools/go/types/typeutil/callee.go

// Callee returns the named target of a function call, if any:
// a function, method, builtin, or variable.
//
// Functions and methods may potentially have type parameters.
func Callee(info *types.Info, call *ast.CallExpr) types.Object { … }

// StaticCallee returns the target (function or method) of a static function
// call, if any. It returns nil for calls to builtins.
//
// Note: for calls of instantiated functions and methods, StaticCallee returns
// the corresponding generic function or method on the generic type.
func StaticCallee(info *types.Info, call *ast.CallExpr) *types.Func { … }

func interfaceMethod(f *types.Func) bool { … }