add

Author: Bascy6

app/src/main/java/hexlet/code/schemas/BaseSchema.java

@@ -1,12 +1,11 @@
 package hexlet.code.schemas;
 
-public abstract class BaseSchema<T extends BaseSchema<T>> {
+public abstract class BaseSchema<T> {
     protected boolean isRequired = false;
 
-    @SuppressWarnings("unchecked")
-    public T required() {
+    public BaseSchema<T> required() {
         this.isRequired = true;
-        return (T) this;
+        return this;
     }
 
     public abstract boolean isValid(Object value);

app/src/main/java/hexlet/code/schemas/MapSchema.java

@@ -2,13 +2,14 @@
 
 import java.util.Map;
 
-public class MapSchema extends BaseSchema<MapSchema> {
+public class MapSchema extends BaseSchema<Map<String, ?>> {
     private int requiredSize = -1;
     private Map<String, BaseSchema<?>> schemas;
 
     @Override
     public MapSchema required() {
-        return super.required();
+        super.required();
+        return this;
     }
 
     public MapSchema sizeof(int size) {

app/src/main/java/hexlet/code/schemas/NumberSchema.java

@@ -1,13 +1,14 @@
 package hexlet.code.schemas;
 
-public class NumberSchema extends BaseSchema<NumberSchema> {
+public class NumberSchema extends BaseSchema<Number> {
     private boolean isPositive = false;
     private int minRange = Integer.MIN_VALUE;
     private int maxRange = Integer.MAX_VALUE;
 
     @Override
     public NumberSchema required() {
-        return super.required();
+        super.required();
+        return this;
     }
 
     public NumberSchema positive() {

app/src/main/java/hexlet/code/schemas/StringSchema.java

@@ -1,12 +1,13 @@
 package hexlet.code.schemas;
 
-public class StringSchema extends BaseSchema<StringSchema> {
+public class StringSchema extends BaseSchema<String> {
     private int minLength = 0;
     private String containsSubstring = null;
 
     @Override
     public StringSchema required() {
-        return super.required();
+        super.required();
+        return this;
     }
 
     public StringSchema minLength(int length) {