def METHOD_NAME():
    """Test cells object."""
    load_custom_mechanisms()
    name = 'test'
    pos = (0., 0., 0.)
    sections = {'soma': Section(L=1, diam=5, Ra=3, cm=100,
                                end_pts=[[0, 0, 0], [0, 39., 0]])}
    synapses = {'ampa': dict(e=0, tau1=0.5, tau2=5.)}
    cell_tree = {
        ('soma', 0): [('soma', 1)]
    }
    sect_loc = {'proximal': 'soma'}
    # GID is assigned exactly once for each cell, either at initialisation...
    cell = Cell(name, pos, sections, synapses, sect_loc, cell_tree, gid=42)
    assert cell.gid == 42
    with pytest.raises(RuntimeError,
                       match='Global ID for this cell already assigned!'):
        cell.gid += 1
    # ... or later
    # cells can exist fine without gid
    cell = Cell(name, pos, sections, synapses, sect_loc, cell_tree)
    assert cell.gid is None  # check that it's initialised to None
    with pytest.raises(ValueError,
                       match='gid must be an integer'):
        cell.gid = [1]
    cell.gid = 42
    assert cell.gid == 42
    with pytest.raises(ValueError,
                       match='gid must be an integer'):
        # test init checks gid
        cell = Cell(name, pos, sections, synapses, sect_loc, cell_tree,
                    gid='one')
    # test that ExpSyn always takes nrn.Segment, not float
    with pytest.raises(TypeError, match='secloc must be instance of'):
        cell.syn_create(0.5, e=0., tau1=0.5, tau2=5.)
    pickle.dumps(cell)  # check cell object is picklable until built
    bad_sections = {'blah': Section(L=1, diam=5, Ra=3, cm=100,
                    end_pts=[[0, 0, 0], [0, 39., 0]])}
    # Check soma must be included in sections
    with pytest.raises(KeyError, match='soma must be defined'):
        cell = Cell(name, pos, bad_sections, synapses, sect_loc, cell_tree)
    sections = {
        'soma': Section(
            L=39,
            diam=20,
            cm=0.85,
            Ra=200.,
            end_pts=[[0, 0, 0], [0, 39., 0]]
        )
    }
    sections['soma'].syns = ['ampa']
    sections['soma'].mechs = {
        'km': {
            'gbar_km': 60
        },
        'ca': {
            'gbar_ca': lambda x: 3e-3 * x
        }
    }
    cell = Cell(name, pos, sections, synapses, sect_loc, cell_tree)
    # test successful build
    cell.build()
    assert 'soma' in cell._nrn_sections
    assert cell._nrn_sections['soma'].L == sections['soma'].L
    assert cell._nrn_sections['soma'].gbar_km == sections[
        'soma'].mechs['km']['gbar_km']
    # test building cell with a dipole oriented to a nonexitent section
    with pytest.raises(ValueError, match='sec_name_apical must be an'):
        cell.build(sec_name_apical='blah')
    # Test section modification
    sec_name = 'soma'
    new_L = 1.0
    new_diam = 2.0
    new_cm = 3.0
    new_Ra = 4.0
    cell.modify_section(sec_name, L=new_L, diam=new_diam, cm=new_cm, Ra=new_Ra)
    # Make sure distance betweeen `Section.end_pts` matches `Section.L`
    new_pts = np.array(cell.sections[sec_name].end_pts)
    new_dist = np.linalg.norm(new_pts[0, :] - new_pts[1, :])
    np.isclose(new_L, new_dist)
    assert cell.sections[sec_name].L == new_L
    assert cell.sections[sec_name].diam == new_diam
    assert cell.sections[sec_name].cm == new_cm
    assert cell.sections[sec_name].Ra == new_Ra
    # Testing update end pts using template cell
    cell1 = pyramidal(cell_name='L5Pyr')
    end_pts_original = list()
    end_pts_new = list()
    for sec_name in cell1.sections.keys():
        section = cell1.sections[sec_name]
        end_pts_original.append(section.end_pts)
        section._L = section._L * 2
        cell1.sections[sec_name] = section
    cell1._update_end_pts()
    for sec_name in cell1.sections.keys():
        end_pts_new.append(cell1.sections[sec_name].end_pts)
    # All coordinates are multiplied by 2 since all section
    # lengths are doubled
    cell1.plot_morphology(show=True)
    for end_pt_original, end_pt_new in zip(end_pts_original, end_pts_new):
        for pt_original, pt_new in zip(end_pt_original, end_pt_new):
            np.testing.assert_almost_equal(list(np.array(pt_original) * 2),
                                           pt_new, 5)
    for sec_name in cell1.sections.keys():
        section = cell1.sections[sec_name]
        section._L = section._L / 2
        cell1.sections[sec_name] = section
    end_pts_new = list()
    cell1._update_end_pts()
    for sec_name in cell1.sections.keys():
        section = cell1.sections[sec_name]
        cell1.sections[sec_name] = section
        end_pts_new.append(section.end_pts)
    cell1.plot_morphology(show=False)
    # Checking equality till 5 decimal places
    np.testing.assert_almost_equal(end_pts_original, end_pts_new, 5)
    # Testing distance function using template cell (L5pyr)
    sec_dist = dict()
    sec_dist['soma'] = 19.5
    sec_dist['apical_trunk'] = 90
    sec_dist['apical_oblique'] = 268.5
    sec_dist['apical_1'] = 481
    sec_dist['apical_2'] = 1161
    sec_dist['apical_tuft'] = 1713.5
    sec_dist['basal_1'] = 42.5
    sec_dist['basal_2'] = 212.5
    sec_dist['basal_3'] = 212.5
    for sec_name in cell1.sections.keys():
        sec_dist_test = cell1.distance_section(sec_name, ('soma', 0))
        assert sec_dist_test == sec_dist[sec_name]