def initialize(self,  **kwargs):
if not set(kwargs.keys()).issuperset(self.init_keys):<EOL><INDENT>raise Exception("<STR_LIT>"<EOL>% '<STR_LIT:U+002C>'.join(repr(el) for el in self.init_keys))<EOL><DEDENT>
Transfer functions may need additional information before the
supplied numpy array can be modified in place. For instance,
transfer functions may have state which needs to be allocated
in memory with a certain size. In other cases, the transfer
function may need to know about the coordinate system
associated with the input data.