Return all the semantic tag related to the given tag id

		:returns: a semantic tag or None
		:rtype: list of ckan.model.semantictag.SemanticTag object

def get(self,id):
		'''Return all the semantic tag related to the given tag id

		:returns: a semantic tag or None
		:rtype: list of ckan.model.semantictag.SemanticTag object

		'''
		query = meta.Session.query(TagSemanticTag).filter(TagSemanticTag.id==id)
		return query.first()