protected function processVariableInString(
        PHP_CodeSniffer_File
        $phpcsFile,
        $stackPtr
    ) {
        $tokens = $phpcsFile->getTokens();
        $token  = $tokens[$stackPtr];

        if (!preg_match_all($this->_double_quoted_variable_regexp, $token['content'], $matches)) {
            return;
        }

        $currScope = $this->findVariableScope($phpcsFile, $stackPtr);
        foreach ($matches[1] as $varName) {
            $varName = $this->normalizeVarName($varName);
            // Are we $this within a class?
            if ($this->checkForThisWithinClass($phpcsFile, $stackPtr, $varName, $currScope)) {
                continue;
            }
            if ($this->checkForSuperGlobal($phpcsFile, $stackPtr, $varName, $currScope)) {
                continue;
            }
            $this->markVariableReadAndWarnIfUndefined($phpcsFile, $varName, $stackPtr, $currScope);
        }
    }