修改方法名。

src/main/java/xyz/zhouxy/plusone/validator/BoolValidator.java

@@ -50,7 +50,7 @@ public class BoolValidator<DTO> extends PropertyValidator<DTO, Boolean, BoolVali
     }
     
     @Override
-    protected BoolValidator<DTO> returnThis() {
+    protected BoolValidator<DTO> thisObject() {
         return this;
     }
 }

src/main/java/xyz/zhouxy/plusone/validator/CollectionValidator.java

@@ -53,7 +53,7 @@ public class CollectionValidator<DTO, T> extends PropertyValidator<DTO, Collecti
     }
 
     @Override
-    protected CollectionValidator<DTO, T> returnThis() {
+    protected CollectionValidator<DTO, T> thisObject() {
         return this;
     }
 }

src/main/java/xyz/zhouxy/plusone/validator/DoubleValidator.java

@@ -29,7 +29,7 @@ public class DoubleValidator<DTO> extends PropertyValidator<DTO, Double, DoubleV
     }
 
     @Override
-    protected DoubleValidator<DTO> returnThis() {
+    protected DoubleValidator<DTO> thisObject() {
         return this;
     }
 }

src/main/java/xyz/zhouxy/plusone/validator/IntValidator.java

@@ -29,7 +29,7 @@ public class IntValidator<DTO> extends PropertyValidator<DTO, Integer, IntValida
     }
 
     @Override
-    protected IntValidator<DTO> returnThis() {
+    protected IntValidator<DTO> thisObject() {
         return this;
     }
 }

src/main/java/xyz/zhouxy/plusone/validator/ObjectValidator.java

@@ -9,7 +9,7 @@ public class ObjectValidator<DTO, T> extends PropertyValidator<DTO, T, ObjectVal
     }
 
     @Override
-    protected ObjectValidator<DTO, T> returnThis() {
+    protected ObjectValidator<DTO, T> thisObject() {
         return this;
     }
 }

src/main/java/xyz/zhouxy/plusone/validator/PropertyValidator.java

@@ -47,7 +47,7 @@ abstract class PropertyValidator<DTO, PROPERTY, THIS> {
 
     public <E extends RuntimeException> THIS notNull(Function<PROPERTY, E> exceptionCreator) {
         withRule(Objects::nonNull, exceptionCreator);
-        return returnThis();
+        return thisObject();
     }
 
     // ====== isNull =====
@@ -62,7 +62,7 @@ abstract class PropertyValidator<DTO, PROPERTY, THIS> {
 
     public <E extends RuntimeException> THIS isNull(Function<PROPERTY, E> exceptionCreator) {
         withRule(Objects::isNull, exceptionCreator);
-        return returnThis();
+        return thisObject();
     }
 
     // ===== equals =====
@@ -83,7 +83,7 @@ abstract class PropertyValidator<DTO, PROPERTY, THIS> {
     public <E extends RuntimeException> THIS equalsThat(
             Object that, Function<PROPERTY, E> exceptionCreator) {
         withRule(value -> Objects.equals(value, that), exceptionCreator);
-        return returnThis();
+        return thisObject();
     }
 
     // ===== state =====
@@ -106,7 +106,7 @@ abstract class PropertyValidator<DTO, PROPERTY, THIS> {
             Predicate<PROPERTY> condition,
             Function<PROPERTY, E> exceptionCreator) {
         withRule(condition, exceptionCreator);
-        return returnThis();
+        return thisObject();
     }
 
     // ========================================================================
@@ -125,5 +125,5 @@ abstract class PropertyValidator<DTO, PROPERTY, THIS> {
         return value -> exceptionSupplier.get();
     }
     
-    protected abstract THIS returnThis();
+    protected abstract THIS thisObject();
 }

src/main/java/xyz/zhouxy/plusone/validator/StringValidator.java

@@ -173,7 +173,7 @@ public class StringValidator<DTO> extends PropertyValidator<DTO, String, StringV
     }
 
     @Override
-    protected StringValidator<DTO> returnThis() {
+    protected StringValidator<DTO> thisObject() {
         return this;
     }
 }