original_string: public function exchange_token($client_id, $client_secret, $redirect_uri, $code = '') {
  		$params = array(
  			'grant_type' => 'authorization_code',
  			'client_id' => $client_id,
  			'client_secret' => $client_secret,
  			'redirect_uri' => $redirect_uri,
  			'code' => $code
  		);
  		return $this->_request('oauth', $params, self::OAUTH_TOKEN_URL);
  	}
code: public function exchange_token($client_id, $client_secret, $redirect_uri, $code = '') {
  		$params = array(
  			'grant_type' => 'authorization_code',
  			'client_id' => $client_id,
  			'client_secret' => $client_secret,
  			'redirect_uri' => $redirect_uri,
  			'code' => $code
  		);
  		return $this->_request('oauth', $params, self::OAUTH_TOKEN_URL);
  	}
code_tokens: public function exchange_token ( $ client_id , $ client_secret , $ redirect_uri , $ code = '' ) { $ params = array ( 'grant_type' => 'authorization_code' , 'client_id' => $ client_id , 'client_secret' => $ client_secret , 'redirect_uri' => $ redirect_uri , 'code' => $ code ) ; return $ this -> _request ( 'oauth' , $ params , self :: OAUTH_TOKEN_URL ) ; }
docstring: Exchange a provided OAuth code for an OAuth access token, 'expires in'
  value and refresh token.
  
  @param $client_id int The Client ID of your registered OAuth application.
  @param $client_secret string The Client Secret of your registered OAuth application.
  @param $redirect_uri string The Redirect URI of your registered OAuth application.
  @param $code string The unique OAuth code to be exchanged for an access token.
  @return A successful response will be an array of the form:
  array(
  'access_token' => The access token to use for API calls
  'expires_in' => The number of seconds until this access token expires
  'refresh_token' => The refresh token to refresh the access token once it expires
  )
  @access public
docstring_tokens: Exchange a provided OAuth code for an OAuth access token expires in value and refresh token .