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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def get(cls, tag_id_or_URI, label=None):
		'''Return the tag with the given id or URI, or None.

		:param tag_id_or_name: the id or name of the tag to return
		:type tag_id_or_name: string

		:returns: the tag object with the given id or name, or None if there is
			no tag with that id or name
		:rtype: ckan.model.tag.Tag

		'''
		# First try to get the tag by ID.
		semantictag = SemanticTag.by_id(tag_id_or_URI)
		if semantictag:
			return semantictag

		else:
			semantictag = SemanticTag.by_URI(tag_id_or_URI)
			return semantictag