How in PyCharm to bind the inclusion of command mode to pressing a key at hand?

Question

vim

I want vim command mode to turn on when I press the 'j' key twice. How can I do that?
I tried to do it through Settings. But if you bind to j, then the key itself stops working. In Sublime Text I did it like this:

{
    "keys": ["j", "j"],
    "command": "exit_insert_mode",
    "context":
    [
        { "key": "setting.command_mode", "operand": false },
        { "key": "setting.is_widget", "operand": false }
    ]
}