in Sources/TwitterTextEditor/Tracer.swift [112:124]
func signpost(name: StaticString,
file: StaticString = #file,
line: Int = #line,
function: StaticString = #function,
_ format: String? = nil,
_ arguments: CVarArg...) -> Signpost
{
signpost(name: name,
file: file,
line: line,
function: function,
format.map { String(format: $0, arguments: arguments) })
}