Read the code carefully

from functools import singledispatchmethod


class Formatter:
    @singledispatchmethod
    def format(self, value: object) -> str:
        return f"unknown: {value!r}"

    @format.register
    def _(self, value: int) -> str:
        return f"int: {value}"

    @format.register
    def _(self, value: list) -> str:
        return f"list of {len(value)}"

    @format.register
    def _(self, value: dict) -> str:
        return f"dict with {len(value)} keys"


f = Formatter()
print(f.format(42))
print(f.format([1, 2, 3]))
print(f.format({"a": 1, "b": 2}))
print(f.format(3.14))
print(f.format(True))

What will the program print? Write here: