sig
  val mk 
    ?loc:Ast_helper.loc ->
    ?attrs:Ast_helper.attrs ->
    Parsetree.object_field_desc -> Parsetree.object_field
  val tag 
    ?loc:Ast_helper.loc ->
    ?attrs:Ast_helper.attrs ->
    Asttypes.label Ast_helper.with_loc ->
    Parsetree.core_type -> Parsetree.object_field
  val inherit_ 
    ?loc:Ast_helper.loc -> Parsetree.core_type -> Parsetree.object_field
end