How to use the mappyfile.find function in mappyfile

NAME "Layer1"
            TYPE POLYGON
        END
        LAYER
            NAME "Layer2"
            TYPE POLYGON
            CLASS
                NAME "Class1"
                COLOR 0 0 -8
            END
        END
    END
    """

    d = mappyfile.loads(s)
    cmp = mappyfile.find(d["layers"], "name", "Layer2")

    assert cmp["name"] == "Layer2"

def dilation(mapfile):

    line = LineString([(0, 0), (1, 1), (0, 2), (2, 2), (3, 1), (1, 0)])
    ll = mappyfile.find(mapfile["layers"], "name", "line")
    ll["features"][0]["wkt"] = "'%s'" % line.wkt

    dilated = line.buffer(0.5, cap_style=3)
    pl = mappyfile.find(mapfile["layers"], "name", "polygon")
    pl["features"][0]["wkt"] = "'%s'" % dilated.wkt

    mapfile["extent"] = " ".join(map(str, dilated.buffer(0.8).bounds))
    return dilated

def erosion(mapfile, dilated):
    """
    We will continue to work with the modified Mapfile
    If we wanted to start from scratch we could simply reread it
    """
    ll = mappyfile.find(mapfile["layers"], "name", "line")
    ll["status"] = "OFF"

    pl = mappyfile.find(mapfile["layers"], "name", "polygon")

    # make a deep copy of the polygon layer in the Map
    # so any modification are made to this layer only
    pl2 = deepcopy(pl)

    pl2["name"] = "newpolygon"       
    mapfile["layers"].append(pl2)

    dilated = dilated.buffer(-0.3)
    pl2["features"][0]["wkt"] = "'%s'" % dilated.wkt

    style = pl["classes"][0]["styles"][0]
    style["color"] = "'#999999'"

STYLE
            COLOR 107 208 107
            OUTLINECOLOR 2 2 2
            WIDTH 1
        END
    END
END
"""

new_layer = mappyfile.loads(new_layer_string)
layers.insert(0, new_layer) # can insert the new layer at any index
assert(layers[0]['name'] == 'land')
# END OF ADD LAYER EXAMPLE
# START OF ADD CLASS EXAMPLE
# find a layer using its name
layer = mappyfile.find(mapfile["layers"], "name", "highlighted")

new_class_string = """
CLASS
    NAME "highlights"
    STYLE
        COLOR 107 208 107
        OUTLINECOLOR 2 2 2
        WIDTH 1
    END
END
"""

new_class = mappyfile.loads(new_class_string)
layer["classes"].insert(1, new_class) # can insert the new class at any index
assert(layer['classes'][1]['name'] == 'land')

def create_frame(mapfile, line, dist):

    # get the polygon layer
    pl = mappyfile.find(mapfile["layers"], "name", "polygon")
    # buffer the line
    dilated = line.buffer(dist, cap_style=3)
    # now set the FEATURES in the Mapfile to be the WKT from Shapely
    pl["features"][0]["wkt"] = "'%s'" % dilated.wkt
    # create an image from this Mapfile
    return create_image("animation_%s" % str(dist), mapfile, format="gif")

def erosion(mapfile, dilated):
    """
    We will continue to work with the modified Mapfile
    If we wanted to start from scratch we could simply reread it
    """
    ll = mappyfile.find(mapfile["layers"], "name", "line")
    ll["status"] = "OFF"

    pl = mappyfile.find(mapfile["layers"], "name", "polygon")

    # make a deep copy of the polygon layer in the Map
    # so any modification are made to this layer only
    pl2 = deepcopy(pl)

    pl2["name"] = "newpolygon"       
    mapfile["layers"].append(pl2)

    dilated = dilated.buffer(-0.3)
    pl2["features"][0]["wkt"] = "'%s'" % dilated.wkt

    style = pl["classes"][0]["styles"][0]
    style["color"] = "'#999999'"
    style["outlinecolor"] = "'#b2b2b2'"

def dilation(mapfile):

    line = LineString([(0, 0), (1, 1), (0, 2), (2, 2), (3, 1), (1, 0)])
    ll = mappyfile.find(mapfile["layers"], "name", "line")
    ll["features"][0]["wkt"] = "'%s'" % line.wkt

    dilated = line.buffer(0.5, cap_style=3)
    pl = mappyfile.find(mapfile["layers"], "name", "polygon")
    pl["features"][0]["wkt"] = "'%s'" % dilated.wkt

    mapfile["extent"] = " ".join(map(str, dilated.buffer(0.8).bounds))
    return dilated