src/ClassLoader.php
function addPrefixes(array $prefixes, int $type = self::PSR4): void
    {
        foreach ($prefixes as $prefix => $paths) {
            $this->addPrefix($prefix, $paths, $type);
        }
    }
function addPrefixes(array $prefixes, int $type = self::PSR4): void
    {
        foreach ($prefixes as $prefix => $paths) {
            $this->addPrefix($prefix, $paths, $type);
        }
    }
Register a prefix => paths map

@see ClassLoader::addPrefix()