public ConfigDef defineInternal(final String name, final Type type, final Object defaultValue, final Validator validator, final Importance importance, final String documentation) {
        return define(new ConfigKey(name, type, defaultValue, validator, importance, documentation, "", -1, Width.NONE, name, Collections.emptyList(), null, true, null));
    }
Define a new internal configuration. Internal configuration won't show up in the docs and aren't
intended for general use.
@param name              The name of the config parameter
@param type              The type of the config
@param defaultValue      The default value to use if this config isn't present
@param validator         The validator to use in checking the correctness of the config
@param importance        The importance of this config (i.e. is this something you will likely need to change?)
@param documentation     The documentation string for the config
@return This ConfigDef so you can chain calls
clients/src/main/java/org/apache/kafka/common/config/ConfigDef.java