The type of all method functions created with the option Dispatch set to Thing, such as code.
The object MethodFunctionSingle is a type, with ancestor classes FunctionClosure < Function < Thing.
The source of this document is in /build/reproducible-path/macaulay2-1.25.06+ds/M2/Macaulay2/packages/Macaulay2Doc/ov_methods.m2:579:0.