Populate child table

Hi! I’m trying to populate a child table using data located in “Timesheet” DocType and “Timesheet Detail” Doctype but I cannot find the way to merge two “frappe.call”. See the code below:

frappe.ui.form.on("Task", {
	refresh: function(frm) {
		cur_frm.clear_table("registro_de_horas_en_tareas"); 
        frappe.call({
        	method: "frappe.client.get_list",
            args: {
        		doctype: "Timesheet",
                filters: {"task": frm.doc.name},
                limit_page_length: 200,
                order_by: "from_time asc", 
			    fields:["employee_name"]
        	},
        	args: {
        		doctype: "Timesheet Detail",
				parent: "Timesheet", 
                filters: {"task": frm.doc.name},
			    limit_page_length: 200,
				order_by: "from_time asc", 
			    fields:["parent", "activity_type", "from_time", "to_time", "hours", "detalle" ],
        	},
        	callback: function(r) {
        		$.each(r.message, function(index, value) { 
        		    var new_row = frappe.model.add_child(frm.doc, "Registro de horas en tareas", "registro_de_horas_en_tareas");		
					new_row.registro = value["parent"];
					new_row.tipo_de_actividad = value["activity_type"];
					new_row.inicio = value["from_time"];
					new_row.fin = value["to_time"];
					new_row.horas = value["hours"];
					new_row.detalle = value["detalle"];
                    new_row.responsable_de_la_actividad = value["employee_name"]
        	    }); 
			    refresh_field("registro_de_horas_en_tareas");
        	}
		})
	}
})

Now I have two “args” and only the last one is used to populate the child table. How can I solve this?