foreach

[gareth-ib]

for key, binfac in self._empty_bins.items():

makes

foreach( pyjslib_foreachlist( $this->_empty_bins->items() ) as list ( $key, $binfac ) ) {

but should be

foreach( $this->_empty_bins as $key => $binfac ) {

[dan-da]

nice catch. I made a fix in cf1758a that detects this case.