@Override
    public int hashCode() {
        return originals.hashCode();
    }
Instantiates and configures the ConfigProviders. The config providers configs are defined as follows:
config.providers : A comma-separated list of names for providers.
config.providers.{name}.class : The Java class name for a provider.
config.providers.{name}.param.{param-name} : A parameter to be passed to the above Java class on initialization.
returns a map of config provider name and its instance.

@param indirectConfigs          The map of potential variable configs
@param providerConfigProperties The map of config provider configs
@param classNameFilter          Filter for config provider class names
@return map of config provider name and its instance.
clients/src/main/java/org/apache/kafka/common/config/AbstractConfig.java