'When importing an XBlock from XML, this method will parse the license
information out of the XML and attach it to the block.
It is defined here so that classes that use this mixin can simply refer
to this method, rather than reimplementing it in their XML import
functions.'

@classmethod
def parse_license_from_xml(cls, definition, node):

    license = node.get('license', default=None)
    if license:
        definition['license'] = license
    return definition
