You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: m_02_wetland_4p_1s.m
    path of file: ./repos/MARRMoT/MARRMoT/Models/Model files
    
    the code of the file until where you have to start completion: classdef m_02_wetland_4p_1s < MARRMoT_model
% Class for hydrologic conceptual model: Wetland model

% Copyright (C) 2019, 2021 Wouter J.M. Knoben, Luca Trotter
% This file is part of the Modular Assessment of Rainfall-Runoff Models
% Toolbox (MARRMoT).
% MARRMoT is a free software (GNU GPL v3) and distributed WITHOUT ANY
% WARRANTY. See <https://www.gnu.org/licenses/> for details.

% Model reference
% Savenije, H. H. G. (2010). “Topography driven conceptual modelling 
% 
    
function [dS, fluxes] = model_fun(obj, S)
            % parameters
            theta   = obj.theta;
            dw    = theta(1);     % Daily interception [mm]
            betaw = theta(2);     % Soil moisture storage distribution parameter [-]
            swmax = theta(3);     % Maximum soil moisture storage [mm], 
            kw    = theta(4);     % Runoff coefficient [d-1]
            
            
            % delta_t
            delta_t = obj.delta_t;
            
            % stores
            S1 = S(1);
            
            % climate input
            t = obj.t;                             % this time step
            climate_in = obj.input_climate(t,:);   % climate at this step
            P  = climate_in(1);
            Ep = climate_in(2);
            T  = climate_in(3);
            
            % fluxes functions
            flux_pe    = interception_2(P,dw);
            flux_ei    = P - flux_pe;
            flux_ew    = evap_1(S1,Ep,delta_t);
            flux_qwsof = saturation_2(S1,swmax,betaw,flux_pe);
            flux_qwgw  = baseflow_1(kw,S1);

            % stores ODEs
            dS1 = flux_pe - flux_ew - flux_qwsof - flux_qwgw; 
            
            % outputs
            dS = [dS1];
            fluxes = [flux_pe,  flux_ei,  flux_ew,  flux_qwsof, flux_qwgw];
        end