QueryExtensions.
        [Preview API]
        :param :class:`<ExtensionQuery> <azure.devops.v5_1.gallery.models.ExtensionQuery>` extension_query:
        :param str account_token:
        :param String account_token_header: Header to pass the account token
        :rtype: :class:`<ExtensionQueryResult> <azure.devops.v5_1.gallery.models.ExtensionQueryResult>`

def query_extensions(self, extension_query, account_token=None, account_token_header=None):
        """QueryExtensions.
        [Preview API]
        :param :class:`<ExtensionQuery> <azure.devops.v5_1.gallery.models.ExtensionQuery>` extension_query:
        :param str account_token:
        :param String account_token_header: Header to pass the account token
        :rtype: :class:`<ExtensionQueryResult> <azure.devops.v5_1.gallery.models.ExtensionQueryResult>`
        """
        query_parameters = {}
        if account_token is not None:
            query_parameters['accountToken'] = self._serialize.query('account_token', account_token, 'str')
        content = self._serialize.body(extension_query, 'ExtensionQuery')
        response = self._send(http_method='POST',
                              location_id='eb9d5ee1-6d43-456b-b80e-8a96fbc014b6',
                              version='5.1-preview.1',
                              query_parameters=query_parameters,
                              content=content)
        return self._deserialize('ExtensionQueryResult', response)