pub fn get(
  input_map: MidiInputMap,
  key key: String,
) -> Result(MidiInput, Nil)

pub fn has(input_map: MidiInputMap, key key: String) -> Bool

pub fn map(
  input_map: MidiInputMap,
  with fun: fn(String, MidiInput) -> a,
) -> a

pub fn size(input_map: MidiInputMap, key key: String) -> Int