add

Author: Bascy6

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

@@ -3,9 +3,10 @@
 public abstract class BaseSchema<T> {
     protected boolean isRequired = false;
 
-    public BaseSchema<T> required() {
+    @SuppressWarnings("unchecked")
+    public T required() {
         this.isRequired = true;
-        return this;
+        return (T) this;
     }
 
     public abstract boolean isValid(Object value);

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

@@ -2,7 +2,7 @@
 
 import java.util.Map;
 
-public class MapSchema extends BaseSchema<Map<String, ?>> {
+public class MapSchema extends BaseSchema<MapSchema> {
     private int requiredSize = -1;
     private Map<String, BaseSchema<?>> schemas;
 
@@ -17,8 +17,8 @@ public MapSchema sizeof(int size) {
         return this;
     }
 
-    public MapSchema shape(Map<String, BaseSchema<?>> shapeSchemas) {
-        this.schemas = shapeSchemas;
+    public MapSchema shape(Map<String, ? extends BaseSchema<?>> shapeSchemas) {
+        this.schemas = (Map<String, BaseSchema<?>>) shapeSchemas;
         return this;
     }
 

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

@@ -1,6 +1,6 @@
 package hexlet.code.schemas;
 
-public class NumberSchema extends BaseSchema<Number> {
+public class NumberSchema extends BaseSchema<NumberSchema> {
     private boolean isPositive = false;
     private int minRange = Integer.MIN_VALUE;
     private int maxRange = Integer.MAX_VALUE;

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

@@ -1,6 +1,6 @@
 package hexlet.code.schemas;
 
-public class StringSchema extends BaseSchema<String> {
+public class StringSchema extends BaseSchema<StringSchema> {
     private int minLength = 0;
     private String containsSubstring = null;