def METHOD_NAME(blk):
    """
    General method for costing membrane aerated biofilm reactor. Capital cost
    is based on the cost of reactor and blower.
    This method also registers the electricity demand as a costed flow.
    """
    t0 = blk.flowsheet().time.first()
    # Get parameter dict from database
    parameter_dict = blk.unit_model.config.database.get_unit_operation_parameters(
        blk.unit_model._tech_type, subtype=blk.unit_model.config.process_subtype
    )
    # Get costing parameter sub-block for this technology
    A, B = blk.unit_model._get_tech_parameters(
        blk,
        parameter_dict,
        blk.unit_model.config.process_subtype,
        ["reactor_cost", "blower_cost"],
    )
    # Add cost variable and constraint
    blk.capital_cost = pyo.Var(
        initialize=1,
        units=blk.config.flowsheet_costing_block.base_currency,
        bounds=(0, None),
        doc="Capital cost of unit operation",
    )
    DCC_reactor = pyo.units.convert(
        blk.unit_model.properties_treated[t0].flow_mass_comp["ammonium_as_nitrogen"]
        / blk.unit_model.nitrogen_removal_rate
        * A,
        to_units=blk.config.flowsheet_costing_block.base_currency,
    )
    DCC_blower = pyo.units.convert(
        blk.unit_model.reactor_area * blk.unit_model.air_flow_rate[t0] * B,
        to_units=blk.config.flowsheet_costing_block.base_currency,
    )
    expr = DCC_reactor + DCC_blower
    blk.unit_model._add_cost_factor(
        blk, parameter_dict["capital_cost"]["cost_factor"]
    )
    blk.capital_cost_constraint = pyo.Constraint(
        expr=blk.capital_cost == blk.cost_factor * expr
    )
    # Register flows
    blk.config.flowsheet_costing_block.cost_flow(
        blk.unit_model.electricity[t0], "electricity"
    )