def add_material(self, material):
        if self.has_material(material): return
        self.materials.append(material)
read GSECARS MCA file to larch group
dataset/ETHPy150Open greenmoss/PyWavefront/pywavefront/mesh.py/Mesh.add_material--crossover with--dataset/ETHPy150Open xraypy/xraylarch/plugins/io/gse_mcafile.py/gsemca_group