Slick.php
/**
     * Registers an error handler to handle exceptions thrown when the app is run.
     *
     * @param callable $handler
     * @return $this
     */
Registers an error handler to handle exceptions thrown when the app is run.
@param callable $handler
@return $this
Registers an error handler to handle exceptions thrown when the app is run . @param callable $handler @return $this
public function onErr(callable $handler): self
    {
        $this->errorHandler = $handler;
        return $this;
    }
public function onErr ( callable $ handler ) : self { $ this -> errorHandler = $ handler ; return $ this ; }
Registers an error handler to handle exceptions thrown when the app is run.
Registers an error handler to handle exceptions thrown when the app is run .