code: public static AssignedAddOnExtensionReader reader(final String pathAccountSid, 
                                                        final String pathResourceSid, 
                                                        final String pathAssignedAddOnSid) {
          return new AssignedAddOnExtensionReader(pathAccountSid, pathResourceSid, pathAssignedAddOnSid);
      }
docs: Create a AssignedAddOnExtensionReader to execute read.
  
  @param pathAccountSid The SID of the Account that created the resources to
  read
  @param pathResourceSid The SID of the Phone Number to which the Add-on is
  assigned
  @param pathAssignedAddOnSid The SID that uniquely identifies the assigned
  Add-on installation
  @return AssignedAddOnExtensionReader capable of executing the read