How to use the hpccm.common.cpu_arch function in hpccm

def test_detect_ppc64le(self):
        """Base image CPU architecture detection"""
        b = baseimage(image='ppc64le/centos:7')
        self.assertEqual(hpccm.config.g_cpu_arch, cpu_arch.PPC64LE)

self.__icc = kwargs.get('icc', True)
        self.__ifort = kwargs.get('ifort', True)
        self.__ipp = kwargs.get('ipp', True)
        self.__mkl = kwargs.get('mkl', True)
        self.__mpi = kwargs.get('mpi', True)
        self.__psxevars = kwargs.get('psxevars', True)
        self.__ospackages = kwargs.get('ospackages', [])
        self.__tbb = kwargs.get('tbb', True)
        self.__version = kwargs.get('version', '2020.1-12')
        self.__year = self.__version.split('.')[0]

        self.__bashrc = ''            # Filled in by __distro()
        self.__apt = []               # Filled in by __setup()
        self.__yum = []               # Filled in by __setup()

        if hpccm.config.g_cpu_arch != cpu_arch.X86_64: # pragma: no cover
            logging.warning('Using intel_psxe_runtime on a non-x86_64 processor')

        # Set the Linux distribution specific parameters
        self.__distro()

        # Construct the list of runtime packages to install
        self.__setup()

        # Fill in container instructions
        self.__instructions()

def __cpu_arch(self):
        """Based on the CPU architecture, set values accordingly.  A user
        specified value overrides any defaults."""

        if hpccm.config.g_cpu_arch == cpu_arch.AARCH64:
            # Bug in the VisIt build config
            self.__arch = 'linux-intel'
        elif hpccm.config.g_cpu_arch == cpu_arch.X86_64:
            self.__arch = 'linux-x86_64'
        else: # pragma: no cover
            raise RuntimeError('Unknown CPU architecture')

def __cpu_arch(self):
        """Based on the CPU architecture, set values accordingly.  A user
        specified value overrides any defaults."""

        if hpccm.config.g_cpu_arch == cpu_arch.AARCH64:
            self.__arch_directory = 'aarch64'
            self.__arch_pkg = 'aarch64'
        elif hpccm.config.g_cpu_arch == cpu_arch.X86_64:
            self.__arch_directory = 'x64'
            self.__arch_pkg = 'x86_64'
        else: # pragma: no cover
            raise RuntimeError('Unknown CPU architecture')

def __make(self):
        """Based on the CPU architecture, set values accordingly.  A user
        specified value overrides any defaults."""

        if not self.__make_opts:
            if self.__toolchain.CC:
                self.__make_opts.append('CC={}'.format(self.__toolchain.CC))
            if self.__toolchain.FC:
                self.__make_opts.append('FC={}'.format(self.__toolchain.FC))

            if hpccm.config.g_cpu_arch == cpu_arch.AARCH64:
                self.__make_opts.extend(['TARGET=ARMV8', 'USE_OPENMP=1'])
            elif hpccm.config.g_cpu_arch == cpu_arch.PPC64LE:
                self.__make_opts.extend(['TARGET=POWER8', 'USE_OPENMP=1'])
            elif hpccm.config.g_cpu_arch == cpu_arch.X86_64:
                self.__make_opts.extend(['USE_OPENMP=1'])
            else: # pragma: no cover
                raise RuntimeError('Unknown CPU architecture')

def __cpu_arch(self):
        """Based on the CPU architecture, set values accordingly.  A user
        specified value overrides any defaults."""

        if hpccm.config.g_cpu_arch == cpu_arch.AARCH64:
            self.__arch_directory = 'aarch64'
            self.__arch_pkg = 'aarch64'
        elif hpccm.config.g_cpu_arch == cpu_arch.X86_64:
            self.__arch_directory = 'x64'
            self.__arch_pkg = 'x86_64'
        else: # pragma: no cover
            raise RuntimeError('Unknown CPU architecture')

'libdapl2', 'libdapl-dev',
                                     'libibcm1', 'libibcm-dev',
                                     'libibmad5', 'libibmad-dev',
                                     'libibverbs1', 'libibverbs-dev',
                                     'libmlx4-1', 'libmlx4-dev',
                                     'libmlx5-1', 'libmlx5-dev',
                                     'librdmacm1', 'librdmacm-dev',
                                     'rdmacm-utils']

                if hpccm.config.g_cpu_arch == cpu_arch.AARCH64:
                    # Ubuntu 16.04 for ARM is missing these packages
                    for missing in ['dapl2-utils', 'libdapl2', 'libdapl-dev',
                                    'libibcm1', 'libibcm-dev']:
                        if missing in self.__ospackages:
                            self.__ospackages.remove(missing)
                elif hpccm.config.g_cpu_arch == cpu_arch.PPC64LE:
                    # Ubuntu 16.04 for Power is missing these packages
                    for missing in ['libibcm1', 'libibcm-dev']:
                        if missing in self.__ospackages:
                            self.__ospackages.remove(missing)
        elif hpccm.config.g_linux_distro == linux_distro.CENTOS:
            self.__extra_opts = [r'--disablerepo=mlnx\*']

            if hpccm.config.g_linux_version >= StrictVersion('8.0'):
                self.__deppackages = ['libnl3', 'numactl-libs']
                self.__ospackages = ['libibmad', 'libibmad-devel',
                                     'libibumad', 'libibverbs',
                                     'libibverbs-utils', 'libmlx5',
                                     'librdmacm',
                                     'rdma-core', 'rdma-core-devel']
                self.__powertools = True
            else:

def __cpu_arch(self):
        """Based on the CPU architecture, set values accordingly.  A user
        specified value overrides any defaults."""

        if hpccm.config.g_cpu_arch == cpu_arch.AARCH64:
            if not self.__target_architecture:
                self.__target_architecture = 'multicore-arm8'
        elif hpccm.config.g_cpu_arch == cpu_arch.PPC64LE:
            if not self.__target_architecture:
                self.__target_architecture = 'multicore-linux-ppc64le'
        elif hpccm.config.g_cpu_arch == cpu_arch.X86_64:
            if not self.__target_architecture:
                self.__target_architecture = 'multicore-linux-x86_64'
        else: # pragma: no cover
            raise RuntimeError('Unknown CPU architecture')