Couldn't find CelMutableExpr in repo here - https://github.com/google/cel-spec. So, believe this is an internal change.

PiperOrigin-RevId: 806154757

Author: CEL Dev Team

common/src/main/java/dev/cel/common/ast/CelMutableExpr.java

@@ -1034,6 +1034,10 @@ public static CelMutableExpr ofMap(long id, CelMutableMap mutableMap) {
     return new CelMutableExpr(id, mutableMap);
   }
 
+  public static CelMutableExpr ofComprehension(CelMutableComprehension mutableComprehension) {
+    return ofComprehension(0, mutableComprehension);
+  }
+
   public static CelMutableExpr ofComprehension(
       long id, CelMutableComprehension mutableComprehension) {
     return new CelMutableExpr(id, mutableComprehension);

common/src/test/java/dev/cel/common/ast/CelMutableExprTest.java

@@ -600,6 +600,35 @@ public void mutableMap_deepCopy() {
         .containsExactlyElementsIn(deepCopiedExpr.map().entries());
   }
 
+  @Test
+  public void ofComprehension() {
+    CelMutableExpr mutableExpr =
+        CelMutableExpr.ofComprehension(
+            CelMutableComprehension.create(
+                "iterVar",
+                CelMutableExpr.ofList(
+                    CelMutableList.create(CelMutableExpr.ofConstant(CelConstant.ofValue(true)))),
+                "accuVar",
+                CelMutableExpr.ofConstant(CelConstant.ofValue(true)),
+                CelMutableExpr.ofConstant(CelConstant.ofValue(true)),
+                CelMutableExpr.ofConstant(CelConstant.ofValue(true)),
+                CelMutableExpr.ofIdent("__result__")));
+
+    assertThat(mutableExpr.id()).isEqualTo(0L);
+    assertThat(mutableExpr.comprehension())
+        .isEqualTo(
+            CelMutableComprehension.create(
+                "iterVar",
+                "",
+                CelMutableExpr.ofList(
+                    CelMutableList.create(CelMutableExpr.ofConstant(CelConstant.ofValue(true)))),
+                "accuVar",
+                CelMutableExpr.ofConstant(CelConstant.ofValue(true)),
+                CelMutableExpr.ofConstant(CelConstant.ofValue(true)),
+                CelMutableExpr.ofConstant(CelConstant.ofValue(true)),
+                CelMutableExpr.ofIdent("__result__")));
+  }
+
   @Test
   public void ofComprehension_withId() {
     CelMutableExpr mutableExpr =