style(ir.attachment.facturae.mx): pylint analysis

l10n_mx_ir_attachment_facturae/models/ir_attachment_facturae.py

@@ -117,6 +117,7 @@ def parse_xml_string(xmlstr):
 
 
 class IrAttachmentFacturaeMx(models.Model):
+    # pylint: disable=R0904
     _name = "ir.attachment.facturae.mx"
     _inherit = ["mail.thread", "ir.needaction_mixin"]
     _rec_name = "uuid"
@@ -418,7 +419,8 @@ class IrAttachmentFacturaeMx(models.Model):
             raise UserError(_("You can't delete signed CFDI!\nPlease cancel it first"))
         return super(IrAttachmentFacturaeMx, self).unlink()
 
-    def action_sign_sat(self, param_pacs, xml_data):
+    @classmethod
+    def action_sign_sat(cls, param_pacs, xml_data):
         """Function use to sign XML in SAT
 
         This function using param_pacs parameter try to sign XML in SAT
@@ -705,7 +707,8 @@ class IrAttachmentFacturaeMx(models.Model):
             self.file_xml_sign.index_content, attrib, element=element
         )
 
-    def parse_data(self, data, attrib, element="*", namespaces=None):
+    @classmethod
+    def parse_data(cls, data, attrib, element="*", namespaces=None):
         """Return value for given attribute
 
         This function looks for an attribute named as attrib parameter into