public class ParamInfo<V> {
    ParamInfo(String name, String[] alias, String description, boolean isOptional, boolean hasDefaultValue, V defaultValue, ParamValidator<V> validator, Class<V> valueClass) {...}

    public String getName() {...}

    public String[] getAlias() {...}

    public String getDescription() {...}

    public boolean isOptional() {...}

    public boolean hasDefaultValue() {...}

    public V getDefaultValue() {...}

    public ParamValidator<V> getValidator() {...}

    public Class<V> getValueClass() {...}
}

public interface WithParams<T> {
    Params getParams();

    default <V> T set(ParamInfo<V> info, V value) {
        getParams().set(info, value);
        return (T) this;
    }

    default <V> V get(ParamInfo<V> info) {
        return getParams().get(info);
    }
}

public class ParamInfoFactory {

    public static <V> ParamInfoBuilder<V> createParamInfo(String name, Class<V> valueClass) {...}

    public static class ParamInfoBuilder<V> {
        ParamInfoBuilder(String name, Class<V> valueClass) {...}

        public ParamInfoBuilder<V> setAlias(String[] alias) {...}

        public ParamInfoBuilder<V> setDescription(String description) {...}

        public ParamInfoBuilder<V> setOptional() {...}

        public ParamInfoBuilder<V> setRequired() {...}

        public ParamInfoBuilder<V> setHasDefaultValue(V defaultValue) {...}

        public ParamInfoBuilder<V> setValidator(ParamValidator<V> validator) {...}

        public ParamInfo<V> build() {...}
    }
}

public class Params implements Serializable, Cloneable {
    public int size() {...}

    public void clear() {...}

    public boolean isEmpty() {...}

    public <V> V get(ParamInfo<V> info) {...}

    public <V> Params set(ParamInfo<V> info, V value) {...}

    public <V> void remove(ParamInfo<V> info) {...}

    public <V> boolean contains(ParamInfo<V> info) {...}

    public String toJson() {...}

    public void loadJson(String json) {...}

    public static Params fromJson(String json) {...}

    public Params merge(Params otherParams) {...}

    public Params clone() {...}
}

/**
 * Definition of a parameter, including name, class, description, default value and the validator.
 *
 * @param <T> The type of the parameter value
 */
public class Param<T> {
    public final String name;
    public final Class<?> clazz;
    public final String description;
    public final Object defaultValue;
    public final ParamValidator validator;

    public Param(String name, Class<?> clazz, String description, Object defaultValue, ParamValidator validator) {...}

    // Encodes the given object into a json-formatted string
    public String jsonEncode(T value) throws IOException {...}

    // Decodes the json-formatted string into an object of the given type.
    public T jsonDecode(String json) throws IOException {...}
}

/**
 * Interface for classes that take parameters. It provides APIs to set and get parameters.
 *
 * @param <T> The class type of WithParams implementation itself.
 */
@PublicEvolving
public interface WithParams<T> {
    /** Gets a param by name. */
    default Param<?> getParam(String name) {...}

    /**
     * Sets the value of the given parameter in the user-defined map.
     *
     * @param param the parameter
     * @param value the value
     * @return the WithParams instance itself
     */
    default T set(Param<?> param, Object value) {...}

    /**
     * Gets the value of the given parameter. Returns the value from the user-defined map if set(...) has been
     * explicitly called to set value for this parameter. Otherwise, returns the default value from the definition of
     * this parameter.
     *
     * @param param the parameter
     * @param <V> the type of the parameter
     * @return the value of the parameter
     */
    default <V> V get(Param<V> param) {...}

    /**
     * Returns an immutable map that contains value for every parameter that meets one of the following conditions:
     * 1) set(...) has been called to set value for this parameter.
     * 2) The parameter is a field of this WithParams instance. This includes public, protected and private fields. And
     * this also includes fields inherited from its interfaces and super-classes.
     *
     * @return an immutable map of parameters and values.
     */
    default Map<Param<?>, Object> getParamMap() {...}

    /**
     * Returns a mutable map that can be used to set values for parameters. A subclass of this interface should override
     * this method if it wants to support users to set non-default parameter values.
     *
     * @return a mutable map of parameters and value overrides.
     */
    default Map<Param<?>, Object> getUserDefinedParamMap() {
        return null;
    }
}