def dataset(self, identifier):
if isinstance(identifier, dict):<EOL><INDENT>identifier = identifier.get('<STR_LIT:id>', identifier['<STR_LIT>'])<EOL><DEDENT>j, _ = self.request('<STR_LIT:GET>', '<STR_LIT>' + str(identifier))<EOL>return j<EOL>
::

    GET /:login/datasets/:id

:param identifier: unique ID or URN for a dataset
:type identifier: :py:class:`basestring` or :py:class:`dict`

:rtype: :py:class:`dict`

Gets a single dataset identified by the unique ID or URN. URNs are 
also prefix-matched. If passed a dict that contains an `urn` or `id` 
key, it uses the respective value as the identifier.