def __add__(self, other):
if ICollection.providedBy(other):
copy = self.copy()
for component in other:
copy.append(component)
return copy
if IComponent.providedBy(other):
copy = self.copy()
copy.append(other)
return copy
raise NotImplementedError
def extend(self, *components):
for cmp in components:
if self.type.providedBy(cmp):
self.append(cmp)
elif ICollection.providedBy(cmp):
for item in cmp:
self.append(item)
else:
if self.factory is not None:
loadComponents()
factory = self.factory(cmp, default=None)
if factory is not None:
for item in factory.produce():
self.append(item)
continue
raise TypeError(u'Invalid type', cmp)
