original_string: public function authenticate()
      {
          $object = 'login';
          $url = sprintf('/api/%s/version/%s', $object, $this->version);
          $parameters = array(
              'email'    => $this->email,
              'password' => $this->password,
              'user_key' => $this->userKey,
              'format'   => $this->format
          );
  
          $this->apiKey = $this->doPost($object, $url, $parameters);
  
          return $this->apiKey;
      }
code: public function authenticate()
      {
          $object = 'login';
          $url = sprintf('/api/%s/version/%s', $object, $this->version);
          $parameters = array(
              'email'    => $this->email,
              'password' => $this->password,
              'user_key' => $this->userKey,
              'format'   => $this->format
          );
  
          $this->apiKey = $this->doPost($object, $url, $parameters);
  
          return $this->apiKey;
      }
code_tokens: public function authenticate ( ) { $ object = 'login' ; $ url = sprintf ( '/api/%s/version/%s' , $ object , $ this -> version ) ; $ parameters = array ( 'email' => $ this -> email , 'password' => $ this -> password , 'user_key' => $ this -> userKey , 'format' => $ this -> format ) ; $ this -> apiKey = $ this -> doPost ( $ object , $ url , $ parameters ) ; return $ this -> apiKey ; }
docstring: Make a call to the login endpoint and obtain an API key
  
  This step is not absolutely necessary, because the post method will check
  for the presence of a key and will call this method if there is none.
  
  @access public
  
  @return void
docstring_tokens: Make a call to the login endpoint and obtain an API key