Remove the validator IS_IN_USET. It is in plugin_dbui and not used here.

docs/api/generated/is_in_uset/my_validators.IS_IN_USET.formatter.rst

-my_validators.IS_IN_USET.formatter
-==================================
-
-.. currentmodule:: my_validators
-
-.. automethod:: IS_IN_USET.formatter
\ No newline at end of file

docs/api/generated/is_in_uset/my_validators.IS_IN_USET.options.rst

-my_validators.IS_IN_USET.options
-================================
-
-.. currentmodule:: my_validators
-
-.. automethod:: IS_IN_USET.options
\ No newline at end of file

docs/api/generated/my_validators.IS_IN_USET.rst

-my_validators.IS_IN_USET
-========================
-
-.. currentmodule:: my_validators
-
-.. autoclass:: IS_IN_USET
-   :show-inheritance:
-
-   .. autosummary::
-      :toctree: is_in_uset/
-
-      ~IS_IN_USET.formatter
-      ~IS_IN_USET.options
-
-
-
-
-

docs/api/index.rst

@@ -12,7 +12,6 @@ API Documentation
     callback
     report
     selector
-    validator
 
 Indices and tables
 ==================

docs/api/report.rst

 
-Report objects
---------------
+Reports
+-------
 
 A collection of methods and classes to build report: *list*, *graph* or
-*metrics*.
+*metric*.
 
 Helper functions
 ^^^^^^^^^^^^^^^^

docs/api/validator.rst

-
-Validators
-----------
-
-
-Classes
-^^^^^^^
-
-    .. currentmodule:: my_validators
-
-    .. autosummary::
-       :toctree: generated/
-
-        ~IS_IN_USET

models/common_settings.py

@@ -8,7 +8,6 @@ import plugin_dbui as dbui
 from datetime import datetime
 from callbacks import INHIBIT_CASCADE_DELETE
 from gluon.tools import PluginManager
-from my_validators import IS_IN_USET
 
 #-------------------------------------------------------------------------------
 #

modules/my_validators.py

-""" Custom validators.
-
-"""
-from gluon.validators import IS_IN_SET
-
-
-class IS_IN_USET(IS_IN_SET):
-    """IS_IN_SET validator but working with unicode string.
-
-        Args:
-            theset (list or tuple or dict):
-                the reference set containing utf-8 strings.
-
-        Keyword Args:
-            **kwargs (dict):
-                the keyword arguments of the validator ``IS_IN_SET``.
-
-    """
-    def __init__(self, theset, **kwargs):
-
-        myset = []
-
-        if isinstance(theset, (list, tuple)):
-            for el in theset:
-                if isinstance(el, unicode):
-                    el = el.encode("utf-8")
-                myset.append(el)
-
-        elif isinstance(theset, dict):
-            myset = {}
-            for key in theset:
-                if isinstance(key, unicode):
-                    myset[key.encode("utf-8")] = theset[key]
-                else:
-                    myset[key] = theset[key]
-
-        IS_IN_SET.__init__(self, myset, **kwargs)
-
-    def __call__(self, value):
-
-        if isinstance(value, unicode):
-            value = value.encode("utf-8")
-
-        return IS_IN_SET.__call__(self, value)