#### §4.1.(c) Callin declaration

A callin binding composes an existing role method with a given base method. It may appear within the role class at any place where feature declarations are allowed. It is denoted by

    role_method_designator <- callin_modifier base_method_designator;

Just like with callout bindings, method designators may or may not contain parameters lists and return type but no modifiers; also, each method designator must exactly and uniquely select one method (cf. §3.1.(c)).
For callin modifiers see below (§4.2).