<PackageReference Include="NETStandard.Library" Version="2.0.1" />

System.Net.Http.Headers.HttpHeaders

public abstract class HttpHeaders : IEnumerable<KeyValuePair<string, IEnumerable<string>>>, IEnumerable
namespace System.Net.Http.Headers { public abstract class HttpHeaders : IEnumerable<KeyValuePair<string, IEnumerable<string>>>, IEnumerable { protected HttpHeaders(); public void Add(string name, IEnumerable<string> values); public void Add(string name, string value); public void Clear(); public bool Contains(string name); public IEnumerator<KeyValuePair<string, IEnumerable<string>>> GetEnumerator(); public IEnumerable<string> GetValues(string name); public bool Remove(string name); public bool TryAddWithoutValidation(string name, IEnumerable<string> values); public bool TryAddWithoutValidation(string name, string value); public bool TryGetValues(string name, out IEnumerable<string> values); } }