async _validateOAuthResponse( query, expectedState ) {
		const { token_type, access_token, scope, state } = query;
		if (
			   token_type !== "bearer"
			|| !reToken.test( access_token )
			|| !this._validateScope( String( scope ).split( SEP_SCOPES_OAUTH ) )
			|| state !== expectedState
		) {
			throw new Error( "OAuth token validation error" );
		}

		return await this.login( access_token, false );
	}
Validate the OAuth response after a login attempt
@param {Object} query
@param {string} query.token_type
@param {string} query.access_token
@param {string} query.scope
@param {string} query.state
@param {string} expectedState
@returns {Promise}