code: def add_subcomponent(self, name):
          
          if self.is_unknown() and is_base_datatype(self.datatype):
              # An unknown component can't have a child
              raise ChildNotValid(name, self)
          return self.children.create_element(name)
docs: Create an instance of :class:`SubComponent <hl7apy.core.SubComponent>` having the given name
  
          :param name: the name of the subcomponent to be created (e.g. CE_1)
          :return: an instance of :class:`SubComponent <hl7apy.core.SubComponent>`
  
          >>> c = Component(datatype='CE')
          >>> ce_1 = c.add_subcomponent('CE_1')
          >>> print(ce_1)
          <SubComponent CE_1>
          >>> print(ce_1 in c.children)
          True