static toTimestamp(time) {

    let value = false;

    const parsed = parseFloat(time);
    if (isNaN(parsed)) return false;

    if (typeof time === "string" && time.substring(0, 1) === "+") {
      if (parsed >= 0) value = WebMidi.time + parsed;
    } else {
      if (parsed >= 0) value = parsed;
    }

    return value;

  }
Returns a valid timestamp, relative to the navigation start of the document, derived from the
`time` parameter. If the parameter is a string starting with the "+" sign and followed by a
number, the resulting timestamp will be the sum of the current timestamp plus that number. If
the parameter is a positive number, it will be returned as is. Otherwise, false will be
returned.

@param [time] {number|string} The time string (e.g. `"+2000"`) or number to parse
@return {number|false} A positive number or `false` (if the time cannot be converted)

@since 3.0.0
@static