If this is a false-positive, you can also ignore this issue in your code via the ignore-call annotation
16
$this->fields->/** @scrutinizer ignore-call */
17
each(function ($field) use (&$rules) {
This check looks for calls to methods that do not seem to exist on a given type.
It looks for the method on the type itself as well as in inherited classes or
implemented interfaces.
This is most likely a typographical error or the method has been renamed.