PhpCsFixer\Fixer\FunctionNotation\ReturnTypeDeclarationFixer::fix PHP Method

    public function fix(\SplFileInfo $file, Tokens $tokens)
    {
        for ($index = 0, $limit = $tokens->count(); $index < $limit; ++$index) {
            $token = $tokens[$index];
            if (!$token->isGivenKind(CT::T_TYPE_COLON)) {
                continue;
            }
            if ($tokens[$index - 1]->isWhitespace()) {
                $tokens[$index - 1]->clear();
            }
            ++$index;
            $tokens->ensureWhitespaceAtIndex($index, 0, ' ');
        }
    }