beter handling of model name starting with number

modules/swagger-codegen/src/main/java/io/swagger/codegen/languages/PhpClientCodegen.java

@@ -407,6 +407,12 @@ public class PhpClientCodegen extends DefaultCodegen implements CodegenConfig {
             name = "model_" + name; // e.g. return => ModelReturn (after camelize)
         }
 
+        // model name starts with number
+        if (name.matches("^\\d.*")) {
+            LOGGER.warn(name + " (model name starts with number) cannot be used as model name. Renamed to " + camelize("model_" + name));
+            name = "model_" + name; // e.g. 200Response => Model200Response (after camelize)
+        }
+
         // add prefix and/or suffic only if name does not start wth \ (e.g. \DateTime)
         if (!name.matches("^\\\\.*")) {
             name = modelNamePrefix + name + modelNameSuffix;