@Override
            protected ConfigDef initialConfigDef() {
                // All Transformations get these config parameters implicitly
                return super.initialConfigDef()
                        .define(TransformationStage.PREDICATE_CONFIG, Type.STRING, null, Importance.MEDIUM,
                                "The alias of a predicate used to determine whether to apply this transformation.")
                        .define(TransformationStage.NEGATE_CONFIG, Type.BOOLEAN, false, Importance.MEDIUM,
                                "Whether the configured predicate should be negated.");
            }
Returns an enriched {@link ConfigDef} building upon the {@code ConfigDef}, using the current configuration specified in {@code props} as an input.
<p>
{@code requireFullConfig} specifies whether required config values that are missing should cause an exception to be thrown.
connect/runtime/src/main/java/org/apache/kafka/connect/runtime/ConnectorConfig.java