'Checks if extension arguments are valid
:param blob_type: The blob type that is being uploaded
:type blob_type: ``str``
:param object_size: The (max) size of the object being uploaded
:type object_size: ``int``'

def _check_values(self, blob_type, object_size):

    if (blob_type not in ['BlockBlob', 'PageBlob']):
        raise LibcloudError('Invalid    blob    type', driver=self)
    if (blob_type == 'PageBlob'):
        if (not object_size):
            raise LibcloudError('Max    blob    size    is    mandatory    for    page    blob', driver=self)
        if (object_size % AZURE_PAGE_CHUNK_SIZE):
            raise LibcloudError('Max    blob    size    is    not    aligned    to    page    boundary', driver=self)
