public function find($identifier)
    {
        $this->stringHelper->validate($identifier);

        foreach ($this->symbols as $symbol) {
            if (in_array($identifier, $symbol->getIdentifiers())) {
                return $symbol;
            }
        }

        return null;
    }
public function find($identifier)
    {
        $this->stringHelper->validate($identifier);

        foreach ($this->symbols as $symbol) {
            if (in_array($identifier, $symbol->getIdentifiers())) {
                return $symbol;
            }
        }

        return null;
    }
public function find ( $ identifier ) { $ this -> stringHelper -> validate ( $ identifier ) ; foreach ( $ this -> symbols as $ symbol ) { if ( in_array ( $ identifier , $ symbol -> getIdentifiers ( ) ) ) { return $ symbol ; } } return null ; }
Returns the symbol that has the given identifier.
Returns null if none is found.

@param string $identifier
@return AbstractSymbol|null
Returns the symbol that has the given identifier . Returns null if none is found .