'Return first item that match or contain an aspect. See
:meth:`coalib.bearlib.aspects.aspectbase.get` for further example.
:param aspect: An aspectclass OR name of an aspect.
:return:       An aspectclass OR aspectclass instance, depend on
AspectList content. Return None if no match found.'

def get(self, aspect):

    if (not isaspect(aspect)):
        aspect = coalib.bearlib.aspects[aspect]
    if (aspect in self.exclude):
        return None
    try:
        return next(filter(None, (item.get(aspect) for item in self)))
    except StopIteration:
        return None
