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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def from_model_files(cls, limits, input_model, investigation_time=1.0, simple_mesh_spacing=1.0, complex_mesh_spacing=5.0, mfd_width=0.1, area_discretisation=10.0):
 """ Reads the hazard model from a file :param list limits: Grid configuration [west, east, xspc, south, north, yspc, upper, lower, zspc] :param str input_model: Path to input source model :param float investigation_time: Investigation time of Poisson model :param float simple_mesh_spacing: Rupture mesh spacing of simple fault (km) :param float complex_mesh_spacing: Rupture mesh spacing of complex fault (km) :param float mfd_width: Spacing (in magnitude units) of MFD :param float area_discretisation: Spacing of discretisation of area source (km) """

        converter = SourceConverter(investigation_time,
                                    simple_mesh_spacing,
                                    complex_mesh_spacing,
                                    mfd_width,
                                    area_discretisation)
        sources = []
        for grp in nrml.to_python(input_model, converter):
            sources.extend(grp.sources)
        return cls(limits, sources, area_discretisation)