public function determineNamespace(File $phpcsFile, $stackPtr)
    {
        $tokens = $phpcsFile->getTokens();

        // Check for the existence of the token.
        if (isset($tokens[$stackPtr]) === false) {
            return '';
        }

        // Check for scoped namespace {}.
        if (empty($tokens[$stackPtr]['conditions']) === false) {
            $namespacePtr = $phpcsFile->getCondition($stackPtr, \T_NAMESPACE);
            if ($namespacePtr !== false) {
                $namespace = $this->getDeclaredNamespaceName($phpcsFile, $namespacePtr);
                if ($namespace !== false) {
                    return $namespace;
                }

                // We are in a scoped namespace, but couldn't determine the name. Searching for a global namespace is futile.
                return '';
            }
        }

        /*
         * Not in a scoped namespace, so let's see if we can find a non-scoped namespace instead.
         * Keeping in mind that:
         * - there can be multiple non-scoped namespaces in a file (bad practice, but it happens).
         * - the namespace keyword can also be used as part of a function/method call and such.
         * - that a non-named namespace resolves to the global namespace.
         */
        $previousNSToken = $stackPtr;
        $namespace       = false;
        do {
            $previousNSToken = $phpcsFile->findPrevious(\T_NAMESPACE, ($previousNSToken - 1));

            // Stop if we encounter a scoped namespace declaration as we already know we're not in one.
            if (empty($tokens[$previousNSToken]['scope_condition']) === false && $tokens[$previousNSToken]['scope_condition'] === $previousNSToken) {
                break;
            }

            $namespace = $this->getDeclaredNamespaceName($phpcsFile, $previousNSToken);

        } while ($namespace === false && $previousNSToken !== false);

        // If we still haven't got a namespace, return an empty string.
        if ($namespace === false) {
            return '';
        } else {
            return $namespace;
        }
    }