type func(m namedMetric, other namedMetric) bool of namedMetric.less does not match inferred type func(a namedMetric, b namedMetric) int for func(a E, b E) int

type func(a string, b string) bool of func(a, b string) bool {…} does not match inferred type func(a string, b string) int for func(a E, b E) int