src/FixerFactory.php
public function registerFixer(FixerInterface $fixer, $isCustom)
    {
        $name = $fixer->getName();

        if (isset($this->fixersByName[$name])) {
            throw new \UnexpectedValueException(sprintf('Fixer named "%s" is already registered.', $name));
        }

        if (!$this->nameValidator->isValid($name, $isCustom)) {
            throw new \UnexpectedValueException(sprintf('Fixer named "%s" has invalid name.', $name));
        }

        $this->fixers[] = $fixer;
        $this->fixersByName[$name] = $fixer;

        return $this;
    }
public function registerFixer(FixerInterface $fixer, $isCustom)
    {
        $name = $fixer->getName();

        if (isset($this->fixersByName[$name])) {
            throw new \UnexpectedValueException(sprintf('Fixer named "%s" is already registered.', $name));
        }

        if (!$this->nameValidator->isValid($name, $isCustom)) {
            throw new \UnexpectedValueException(sprintf('Fixer named "%s" has invalid name.', $name));
        }

        $this->fixers[] = $fixer;
        $this->fixersByName[$name] = $fixer;

        return $this;
    }
@param FixerInterface $fixer
@param bool           $isCustom

@return $this