NEW: ExpressionList has clear() method

ebean-api/src/main/java/io/ebean/ExpressionList.java

@@ -1730,4 +1730,8 @@ public interface ExpressionList<T> {
    */
   ExpressionList<T> endNot();
 
+  /**
+   * Clears the current expression list.
+   */
+  ExpressionList<T> clear();
 }

ebean-core/src/main/java/io/ebeaninternal/server/expression/DefaultExpressionList.java

@@ -1268,4 +1268,10 @@ public class DefaultExpressionList<T> implements SpiExpressionList<T> {
     }
     return null;
   }
+
+  @Override
+  public ExpressionList<T> clear() {
+    list.clear();
+    return this;
+  }
 }

ebean-core/src/main/java/io/ebeaninternal/server/expression/JunctionExpression.java

@@ -1068,4 +1068,9 @@ final class JunctionExpression<T> implements SpiJunction<T>, SpiExpression, Expr
     }
     return null;
   }
+
+  @Override
+  public ExpressionList<T> clear() {
+    return exprList.clear();
+  }
 }

ebean-core/src/test/java/io/ebeaninternal/server/expression/DefaultExpressionListTest.java

@@ -99,6 +99,14 @@ public class DefaultExpressionListTest extends BaseExpressionTest {
       .isSameByBind(spi(exp().eq("a", 10).eq("b", 20)))).isFalse();
   }
 
+  @Test
+  public void isSameWithClear() {
+    DefaultExpressionList<?> exp1 = spi(exp().eq("a", 10).eq("b", 20).clear().eq("c", 30));
+    DefaultExpressionList<?> exp2 = spi(exp().eq("c", 30));
+    same(exp1, exp2);
+    assertThat(exp1.isSameByBind(exp2)).isTrue();
+  }
+  
   @SuppressWarnings("unchecked")
   @Test
   void copy() {