def loadModule(self, modName, **userCtx):
        for mibSource in self.__mibSources:
            debug.logger & debug.flagBld and debug.logger('loadModule: trying %s at %s' % (modName, mibSource))
            try:
                modData, sfx = mibSource.read(modName)
            except IOError:
                debug.logger & debug.flagBld and debug.logger(
                    'loadModule: read %s from %s failed: %s' % (modName, mibSource, sys.exc_info()[1]))
                continue

            modPath = mibSource.fullPath(modName, sfx)

            if modPath in self.__modPathsSeen:
                debug.logger & debug.flagBld and debug.logger('loadModule: seen %s' % modPath)
                break
            else:
                self.__modPathsSeen[modPath] = 1

            debug.logger & debug.flagBld and debug.logger('loadModule: evaluating %s' % modPath)

            g = {'mibBuilder': self, 'userCtx': userCtx}

            try:
                exec (modData, g)

            except Exception:
                del self.__modPathsSeen[modPath]
                raise error.MibLoadError(
                    'MIB module \"%s\" load error: %s' % (modPath, traceback.format_exception(*sys.exc_info()))
                )

            self.__modSeen[modName] = modPath

            debug.logger & debug.flagBld and debug.logger('loadModule: loaded %s' % modPath)

            break

        if modName not in self.__modSeen:
            raise error.MibNotFoundError(
                'MIB file \"%s\" not found in search path (%s)' % (
                    modName and modName + ".py[co]", ', '.join([str(x) for x in self.__mibSources]))
            )

        return self