Base class for conservation of mass in the electrolyte.
param (parameter class) – The parameters to use for this submodel
options (dict, optional) – A dictionary of options to be passed to the model.
**Extends (** pybamm.BaseSubModel) –
A method to set events related to the state of submodel variable. Note: this
method modifies the state of self.events. Unless overwritten by a submodel, the
default behaviour of ‘pass’ is used a implemented in
pybamm.BaseSubModel.
variables (dict) – The variables in the whole model.