<PackageReference Include="Microsoft.Extensions.Configuration.Abstractions" Version="1.1.0-preview1-final" />

IConfigurationBuilder

public interface IConfigurationBuilder
Represents a type used to build application configuration.
Dictionary<string, object> Properties { get; }

Gets a key/value collection that can be used to share data between the IConfigurationBuilder and the registered IConfigurationSources.

Gets the sources used to obtain configuation values

Adds a new configuration source.

Builds an IConfiguration with keys and values from the set of sources registered in Sources.