private function getDocCommentFromFile($fileName)
    {
        $lines = file($fileName, FILE_IGNORE_NEW_LINES);

        $declaringClassStartLine = $this->getDeclaringClass()->getStartLine() - 1;
        $declaringClassLength = $this->getDeclaringClass()->getEndLine() - $declaringClassStartLine + 1;

        $currentClassLines = array_slice($lines, $declaringClassStartLine, $declaringClassLength, true);

        // Need the php open tag to tokenize the class.
        $tokens = token_get_all("<?php\n" . implode("\n", $currentClassLines));

        $return = false;
        $constDeclarationKey = $this->getCurrentConstantKeyFromClassTokens($tokens);

        // Now we have the key value of the constant declaration, we have to pick up the comment before the declaration (if it exists).
        for ($constDeclarationKey--; $constDeclarationKey > 0; $constDeclarationKey--) {
            if ($tokens[$constDeclarationKey][0] !== T_WHITESPACE && $tokens[$constDeclarationKey][0] !== T_DOC_COMMENT) {
                break;
            } elseif ($tokens[$constDeclarationKey][0] === T_DOC_COMMENT) {
                $return = $tokens[$constDeclarationKey][1];
                break;
            }
        }

        return $return;
    }