[Refactor] Revisit access modification keywords.

Make some parts of the non-public API less visible and
final.

mapper/src/main/java/com/meistermeier/neo4j/toolbelt/conversion/Converters.java

@@ -39,6 +39,14 @@ public Converters() {
 		this.internalTypeConverters.add(new EntityConverter(this));
 	}
 
+	/**
+	 * Convert given value into target type.
+	 *
+	 * @param mapAccessor input value
+	 * @param type        target type
+	 * @param <T>         resulting target type
+	 * @return			  converted value or throws {@link ConversionException} if no suitable converter can be found
+	 */
 	public <T> T convert(MapAccessor mapAccessor, Class<T> type) {
 		if (mapAccessor instanceof Value value) {
 			for (ValueConverter valueConverter : internalValueConverters) {

mapper/src/main/java/com/meistermeier/neo4j/toolbelt/conversion/DriverValueConverter.java

@@ -35,7 +35,7 @@
  *
  * @author Gerrit Meier
  */
-class DriverValueConverter implements ValueConverter {
+final class DriverValueConverter implements ValueConverter {
 
 	private static final TypeSystem typeSystem = TypeSystem.getDefault();
 	private static final List<Type> SUPPORTED_SOURCE_VALUES_TYPES = List.of(typeSystem.LIST(), typeSystem.NULL());

mapper/src/main/java/com/meistermeier/neo4j/toolbelt/conversion/EntityConverter.java

@@ -28,7 +28,7 @@
  *
  * @author Gerrit Meier
  */
-public class EntityConverter implements TypeConverter<MapAccessor> {
+final class EntityConverter implements TypeConverter<MapAccessor> {
 
 	private final TypeSystem typeSystem = TypeSystem.getDefault();
 	private final ObjectInstantiator objectInstantiator = new ObjectInstantiator();

mapper/src/main/java/com/meistermeier/neo4j/toolbelt/conversion/ObjectInstantiator.java

@@ -15,7 +15,6 @@
  */
 package com.meistermeier.neo4j.toolbelt.conversion;
 
-import com.meistermeier.neo4j.toolbelt.conversion.Converters;
 import org.neo4j.driver.Value;
 import org.neo4j.driver.types.MapAccessor;
 
@@ -75,10 +74,10 @@ <T> Function<MapAccessor, T> createInstance(Class<T> entityClass, Converters con
 		};
 	}
 
-	@SuppressWarnings("unchecked")
 	/**
 	 * Find the constructor with the most matching parameter count.
 	 */
+	@SuppressWarnings("unchecked")
 	private <T> Constructor<T> determineConstructor(Class<T> clazz, Map<String, Object> propertyValue) {
 		Constructor<T>[] constructors = (Constructor<T>[]) clazz.getDeclaredConstructors();
 		Constructor<T> instantiatingConstructorCandidate = null;

mapper/src/main/java/com/meistermeier/neo4j/toolbelt/mapper/Mapper.java

@@ -29,7 +29,7 @@
  *
  * @author Gerrit Meier
  */
-public class Mapper {
+public final class Mapper {
 
 	/**
 	 * A prepared {@link Mapper} instance.
@@ -67,7 +67,7 @@ public <T> Function<Record, Iterable<T>> createCollectionMapperFor(Class<T> type
 		return record -> mapAll(record, type);
 	}
 
-	<T> T mapOne(MapAccessor mapAccessor, Class<T> type) {
+	private <T> T mapOne(MapAccessor mapAccessor, Class<T> type) {
 		return converters.convert(mapAccessor, type);
 	}
 

mapper/src/main/java/com/meistermeier/neo4j/toolbelt/renderer/Neo4jDriverModule.java

@@ -46,7 +46,7 @@ class Neo4jDriverModule extends SimpleModule {
 		addSerializer(LocalTime.class, new Neo4jTypeSerializer<>());
 	}
 
-	private class Neo4jTypeSerializer<T> extends JsonSerializer<T> {
+	private static class Neo4jTypeSerializer<T> extends JsonSerializer<T> {
 
 		@Override
 		public void serialize(T value, JsonGenerator jsonGenerator, SerializerProvider serializerProvider) throws IOException {