Get the component of type component_type associated with entity.

        Long-hand for :func:`essence.Entity.get`.

        :param entity: entity to query
        :type entity: :class:`essence.Entity`
        :param component_type: component to add to the entity
        :type component_type: The :class:`type` of a :class:`Component` subclass
        :param missing: value to return if
        :type missing: :class:`essence.Component`
        :raises:

def get_component(self, entity, component_type, missing=MISSING):
        """Get the component of type component_type associated with entity.

        Long-hand for :func:`essence.Entity.get`.

        :param entity: entity to query
        :type entity: :class:`essence.Entity`
        :param component_type: component to add to the entity
        :type component_type: The :class:`type` of a :class:`Component` subclass
        :param missing: value to return if
        :type missing: :class:`essence.Component`
        :raises:"""
        relation = self._get_relation(component_type)
        if entity not in relation:
            if missing is MISSING:
                raise NoSuchComponentError()
            else:
                return missing
        return relation[entity]