function_exists ( 'ray' )

[carlituxman]

It would be necessary something like this using mu-plugins
if ( !function_exists('ray') ) { function ray() {} }
for production environments

[freekmurze]

I don't understand your remark, but feel free to PR non-breaking improvements.

[carlituxman]

I use mu-plugins, then at production hasn't plugin. Before upload changes to environment production need quit ray() on my code, with this don't needed