ResourceLocator/src/UniformResourceLocator.php
public function isStream($uri)
    {
        try {
            list ($scheme,) = $this->normalize($uri, true, true);
        } catch (\Exception $e) {
            return false;
        }

        return $this->schemeExists($scheme);
    }
public function isStream($uri)
    {
        try {
            list ($scheme,) = $this->normalize($uri, true, true);
        } catch (\Exception $e) {
            return false;
        }

        return $this->schemeExists($scheme);
    }
public function isStream ( $ uri ) { try { list ( $ scheme , ) = $ this -> normalize ( $ uri , true , true ) ; } catch ( \ Exception $ e ) { return false ; } return $ this -> schemeExists ( $ scheme ) ; }
Returns true if uri is resolvable by using locator.

@param  string $uri
@return bool
Returns true if uri is resolvable by using locator .