fix testIf

cpg-language-python/src/main/kotlin/de/fraunhofer/aisec/cpg/frontends/python/PythonAST.kt

@@ -477,7 +477,7 @@ interface PythonAST {
      *
      * ast.expr = class expr(AST)
      */
-    abstract class ExprBase(pyObject: PyObject) : AST(pyObject)
+    abstract class ExprBase(pyObject: PyObject) : AST(pyObject), WithPythonLocation
 
     /**
      * ```

cpg-language-python/src/main/kotlin/de/fraunhofer/aisec/cpg/frontends/python/PythonLanguageFrontend.kt

@@ -104,7 +104,7 @@ class PythonLanguageFrontend(language: Language<PythonLanguageFrontend>, ctx: Tr
                 mutableLines[lastLineIdx].length + physicalLocation.region.startColumn -
                     physicalLocation.region.endColumn
             mutableLines[lastLineIdx] = mutableLines[lastLineIdx].dropLast(toRemove)
-            return mutableLines.toString()
+            return mutableLines.joinToString(separator = "\n") // TODO
         }
         return null
     }

cpg-language-python/src/test/kotlin/de/fraunhofer/aisec/cpg/frontends/python/PythonFrontendTest.kt

@@ -214,17 +214,15 @@ class PythonFrontendTest : BaseTest() {
         val body = main.body as? CompoundStatement
         assertNotNull(body)
 
-        val sel =
-            (body.statements.first() as? DeclarationStatement)?.singleDeclaration
-                as? VariableDeclaration
+        val sel = (body.statements.first() as? AssignExpression)?.declarations?.first()
         assertNotNull(sel)
         assertLocalName("sel", sel)
         assertEquals(tu.primitiveType("bool"), sel.type)
 
-        val initializer = sel.initializer as? Literal<*>
-        assertNotNull(initializer)
-        assertEquals(tu.primitiveType("bool"), initializer.type)
-        assertEquals("True", initializer.code)
+        val firstAssignment = sel.firstAssignment as? Literal<*>
+        assertNotNull(firstAssignment)
+        assertEquals(tu.primitiveType("bool"), firstAssignment.type)
+        assertEquals("True", firstAssignment.code)
 
         val `if` = body.statements[1] as? IfStatement
         assertNotNull(`if`)