Add implementation for lyd_new_meta() as DNode.new_meta()

Author: cristina-defran

cffi/cdefs.h

@@ -1002,6 +1002,7 @@ LY_ERR lyd_merge_module(struct lyd_node **, const struct lyd_node *, const struc
 
 LY_ERR lyd_new_implicit_all(struct lyd_node **, const struct ly_ctx *, uint32_t, struct lyd_node **);
 
+LY_ERR lyd_new_meta(const struct ly_ctx *, struct lyd_node *, const struct lys_module *, const char *, const char *, ly_bool, struct lyd_meta **);
 
 /* from libc, needed to free allocated strings */
 void free(void *);

libyang/data.py

@@ -256,6 +256,19 @@ def meta_free(self, name):
                 lib.lyd_free_meta_single(item)
                 break
 
+    def new_meta(self, name: str, value: str, clear_dflt: bool = False):
+        ret = lib.lyd_new_meta(
+            ffi.NULL,
+            self.cdata,
+            ffi.NULL,
+            str2c(name),
+            str2c(value),
+            clear_dflt,
+            ffi.NULL,
+        )
+        if ret != lib.LY_SUCCESS:
+            raise self.context.error("cannot create meta")
+
     def add_defaults(
         self,
         no_config: bool = False,