moved to flatgraph. only change left: deprecation onlyChecked

Author: mpollmeier

codepropertygraph/src/main/scala/io/shiftleft/Implicits.scala

@@ -5,67 +5,9 @@ import org.slf4j.{Logger, LoggerFactory}
 object Implicits {
   private val logger: Logger = LoggerFactory.getLogger(Implicits.getClass)
 
-  extension [A](iterable: IterableOnce[A]) {
-
-    /** @see {{{loneElement(hint)}}} */
-    def loneElement: A =
-      loneElement(hint = "")
-
-    /** @return
-      *   the one and only element from an Iterable
-      * @throws NoSuchElementException
-      *   if the Iterable is empty
-      * @throws AssertionError
-      *   if the Iterable has more than one element
-      */
-    def loneElement(hint: String): A = {
-      lazy val hintMaybe =
-        if (hint.isEmpty) ""
-        else s" Hint: $hint"
-
-      val iter = iterable.iterator
-      if (iter.isEmpty) {
-        throw new NoSuchElementException(
-          s"Iterable was expected to have exactly one element, but it is empty.$hintMaybe"
-        )
-      } else {
-        val res = iter.next()
-        if (iter.hasNext) {
-          val collectionSizeHint = iterable.knownSize match {
-            case -1 => "it has more than one" // cannot be computed cheaply, i.e. without traversing the collection
-            case knownSize => s"it has $knownSize"
-          }
-          throw new AssertionError(
-            s"Iterable was expected to have exactly one element, but $collectionSizeHint.$hintMaybe"
-          )
-        }
-        res
-      }
-    }
-
-    /** @return
-      *   {{{Some(element)}}} if the Iterable has exactly one element, or {{{None}}} if the Iterable has zero or more
-      *   than 1 element. Note: if the lone element is {{{null}}}, this will return {{{Some(null)}}}, which is in
-      *   accordance with how {{{headOption}}} works.
-      */
-    def loneElementOption: Option[A] = {
-      val iter = iterable.iterator
-      if (iter.isEmpty) {
-        None
-      } else {
-        val result = iter.next()
-        if (iter.hasNext) {
-          None
-        } else {
-          Some(result)
-        }
-      }
-    }
-  }
-
   implicit class IterableOnceDeco[T](val iterable: IterableOnce[T]) extends AnyVal {
     @deprecated(
-      "please use `loneElement` instead, which has a better name and will throw if the iterable has more than one element (rather than just log.warn)",
+      "please use `.loneElement` from flatgraph (mixed into the generated `language` packages) instead, which has a better name and will throw if the iterable has more than one element (rather than just log.warn)",
       since = "1.7.42 (July 2025)"
     )
     def onlyChecked: T = {