namespace System.Diagnostics.Metrics { public sealed class UpDownCounter<T> : Instrument<T> where T : struct { public void Add(T delta); public void Add(T delta, KeyValuePair<string, object> tag); public void Add(T delta, KeyValuePair<string, object> tag1, KeyValuePair<string, object> tag2); public void Add(T delta, KeyValuePair<string, object> tag1, KeyValuePair<string, object> tag2, KeyValuePair<string, object> tag3); public void Add(T delta, ReadOnlySpan<KeyValuePair<string, object>> tags); public void Add(T delta, params KeyValuePair<string, object>[] tags); public void Add(T delta, ref TagList tagList); } }