def mkdir(self, path, attr):
return SFTP_OP_UNSUPPORTED<EOL>
Create a new directory with the given attributes.  The C{attr}
object may be considered a "hint" and ignored.

The C{attr} object will contain only those fields provided by the
client in its request, so you should use C{hasattr} to check for
the presense of fields before using them.  In some cases, the C{attr}
object may be completely empty.

@param path: requested path (relative or absolute) of the new
    folder.
@type path: str
@param attr: requested attributes of the new folder.
@type attr: L{SFTPAttributes}
@return: an SFTP error code like L{SFTP_OK}.
@rtype: int