ConfigurationBuilder
Builds key/value-based configuration settings for use in an application.
            
                
Gets a key/value collection that can be used to share data between the  IConfigurationBuilder
            and the registered  IConfigurationProvider providers.
            
Gets the sources used to obtain configuration values.
            
public ConfigurationBuilder()
Adds a new configuration source.
            
Builds an  IConfiguration with keys and values from the set of providers registered in
             Sources.