The expression $this->processors of type array is implicitly converted to a boolean; are you sure this is intended? If so, consider using ! empty($expr) instead to make it clear that you intend to check for an array without elements.
This check marks implicit conversions of arrays to boolean values in a comparison. While in PHP an
empty array is considered to be equal (but not identical) to false, this is not always apparent.
Consider making the comparison explicit by using empty(..) or !empty(...) instead.
The PSR-2 coding standard requires that all properties in a class have their visibility explicitly declared. If you declare a property using
the property is implicitly global.
To learn more about the PSR-2, please see the PHP-FIG site on the PSR-2.