InternalGainsOccupancy
======================

Overview
--------

Class responsible for handling internal gains due to occupancy.

The InternalOccupancy class calculates the internal gains generated by
occupants in a given building or setting based on the number of people,
gains per person, and occupancy data over time. The result is returned as
a timeseries data structure that reflects the internal gains.


Key facts
---------

- Method key: ``InternalGainsOccupancy``


Requirements
------------

Required keys (specify in objects)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


- ``inhabitants``
- ``gains_internal[W]_per_person[W]``



Optional keys (specify in objects)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


- None


Required data (specify in data)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


- ``occupancy``



Optional data (specify in data)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


- None


Outputs
-------

Summary metrics
~~~~~~~~~~~~~~~


- None


Timeseries columns
~~~~~~~~~~~~~~~~~~


- None


Public methods
--------------


- generate

  .. code-block:: python

         def generate(self, obj, data, ts_type=None):
           num_people = obj.get(O.INHABITANTS)
           gain_per_person = obj[O.GAINS_INTERNAL_PER_PERSON]
           occ = data[Types.OCCUPANCY]

           internal_gains = occ * gain_per_person * num_people

           return pd.DataFrame({O.GAINS_INTERNAL: internal_gains}, index=occ.index)