Add library model for Apache Commons CollectionUtils.isNotEmpty (#932) (#1062)

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- [ ] Added library model for Apache Commons CollectionUtils.isNotEmpty

  - [ ] related to issue #932 

- [ ] `void apacheCollectionsCollectionUtilsIsNotEmpty()` and `void
apacheCollectionsCollectionUtilsIsNotEmpty()` tests have been added to
`FrameworkTests.java`

Author: pochopsp

nullaway/src/main/java/com/uber/nullaway/handlers/LibraryModelsHandler.java

@@ -741,6 +741,16 @@ private static class DefaultLibraryModels implements LibraryModels {
             .put(methodRef("spark.utils.StringUtils", "isNotBlank(java.lang.CharSequence)"), 0)
             .put(methodRef("spark.utils.StringUtils", "hasLength(java.lang.String)"), 0)
             .put(methodRef("spark.utils.StringUtils", "hasLength(java.lang.CharSequence)"), 0)
+            .put(
+                methodRef(
+                    "org.apache.commons.collections.CollectionUtils",
+                    "isNotEmpty(java.util.Collection)"),
+                0)
+            .put(
+                methodRef(
+                    "org.apache.commons.collections4.CollectionUtils",
+                    "isNotEmpty(java.util.Collection<?>)"),
+                0)
             .put(
                 methodRef("org.apache.commons.lang.StringUtils", "isNotEmpty(java.lang.String)"), 0)
             .put(

nullaway/src/test/java/com/uber/nullaway/FrameworkTests.java

@@ -1017,6 +1017,42 @@ public void apacheValidateStringValidIndex() {
         .doTest();
   }
 
+  @Test
+  public void apacheCollectionsCollectionUtilsIsNotEmpty() {
+    defaultCompilationHelper
+        .addSourceLines(
+            "Foo.java",
+            "package com.uber;",
+            "import org.apache.commons.collections.CollectionUtils;",
+            "import org.jetbrains.annotations.Nullable;",
+            "import java.util.List;",
+            "public class Foo {",
+            "  public void bar(@Nullable List<String> s) {",
+            "    if(CollectionUtils.isNotEmpty(s))",
+            "      s.get(0);",
+            "  }",
+            "}")
+        .doTest();
+  }
+
+  @Test
+  public void apacheCollections4CollectionUtilsIsNotEmpty() {
+    defaultCompilationHelper
+        .addSourceLines(
+            "Foo.java",
+            "package com.uber;",
+            "import org.apache.commons.collections4.CollectionUtils;",
+            "import org.jetbrains.annotations.Nullable;",
+            "import java.util.List;",
+            "public class Foo {",
+            "  public void bar(@Nullable List<String> s) {",
+            "    if(CollectionUtils.isNotEmpty(s))",
+            "      s.get(0);",
+            "  }",
+            "}")
+        .doTest();
+  }
+
   @Test
   public void filesIsDirectory() {
     defaultCompilationHelper