code: function getIdPropertyNames(context) {
    const idPropertyNames = context.streamProcessing.idPropertyNames;
    return Array.isArray(idPropertyNames) ? idPropertyNames :
      typeof idPropertyNames === 'string' ? toPropertyNamesArray(idPropertyNames) : [];
  }
docs: Returns the the names of all of the message identifier properties configured on the given context, which are used to
  extract a message's unique identifier(s), which uniquely identifies the message.
  @param {StreamProcessing} context - the context from which to fetch the message id property names
  @returns {string[]} the message id property names if any; otherwise an empty array