php/WP_CLI/Autoloader.php
public function add_namespace(
		$root,
		$base_dir,
		$prefix = '',
		$suffix = '.php',
		$lowercase = false,
		$underscores = false
	) {
		$this->namespaces[] = array(
			'root'        => $this->normalize_root( (string) $root ),
			'base_dir'    => $this->add_trailing_slash( (string) $base_dir ),
			'prefix'      => (string) $prefix,
			'suffix'      => (string) $suffix,
			'lowercase'   => (bool) $lowercase,
			'underscores' => (bool) $underscores,
		);

		return $this;
	}
public function add_namespace(
		$root,
		$base_dir,
		$prefix = '',
		$suffix = '.php',
		$lowercase = false,
		$underscores = false
	) {
		$this->namespaces[] = array(
			'root'        => $this->normalize_root( (string) $root ),
			'base_dir'    => $this->add_trailing_slash( (string) $base_dir ),
			'prefix'      => (string) $prefix,
			'suffix'      => (string) $suffix,
			'lowercase'   => (bool) $lowercase,
			'underscores' => (bool) $underscores,
		);

		return $this;
	}
public function add_namespace ( $ root , $ base_dir , $ prefix = '' , $ suffix = '.php' , $ lowercase = false , $ underscores = false ) { $ this -> namespaces [ ] = array ( 'root' => $ this -> normalize_root ( ( string ) $ root ) , 'base_dir' => $ this -> add_trailing_slash ( ( string ) $ base_dir ) , 'prefix' => ( string ) $ prefix , 'suffix' => ( string ) $ suffix , 'lowercase' => ( bool ) $ lowercase , 'underscores' => ( bool ) $ underscores , ) ; return $ this ; }
Add a specific namespace structure with our custom autoloader.

@param string  $root        Root namespace name.
@param string  $base_dir    Directory containing the class files.
@param string  $prefix      Prefix to be added before the class.
@param string  $suffix      Suffix to be added after the class.
@param boolean $lowercase   Whether the class should be changed to
lowercase.
@param boolean $underscores Whether the underscores should be changed to
hyphens.

@return self
Add a specific namespace structure with our custom autoloader .