src/Fixer/FunctionNotation/VoidReturnFixer.php
private function hasReturnTypeHint(Tokens $tokens, $index)
    {
        $endFuncIndex = $tokens->getPrevTokenOfKind($index, [')']);
        $nextIndex = $tokens->getNextMeaningfulToken($endFuncIndex);

        return $tokens[$nextIndex]->isGivenKind(CT::T_TYPE_COLON);
    }
private function hasReturnTypeHint(Tokens $tokens, $index)
    {
        $endFuncIndex = $tokens->getPrevTokenOfKind($index, [')']);
        $nextIndex = $tokens->getNextMeaningfulToken($endFuncIndex);

        return $tokens[$nextIndex]->isGivenKind(CT::T_TYPE_COLON);
    }
Determine whether the function already has a return type hint.

@param Tokens $tokens
@param int    $index  The index of the end of the function definition line, EG at { or ;

@return bool