code: func (om *OrdMap) Exists(key interface{}) bool {
  	rkey := ty.AssertType(key, om.ktype)
  	return om.exists(rkey)
  }
docs: // Exists has a parametric type:
  //
  //	func (om *OrdMap<K, V>) Exists(key K) bool
  //
  // Exists returns true if `key` is in the map `om`.