Update metric.graphqls (#28)

diff --git a/metric.graphqls b/metric.graphqls
index 55db791..031c0af 100644
--- a/metric.graphqls
+++ b/metric.graphqls
@@ -69,5 +69,10 @@
 extend type Query {
     getValues(metric: BatchMetricConditions!, duration: Duration!): IntValues
     getLinearIntValues(metric: MetricCondition!, duration: Duration!): IntValues
+    # Query the type of metrics including multiple values, and format them as multiple linears.
+    # The seq of these multiple lines base on the calculation func in OAL
+    # Such as, should us this to query the result of func percentile(50,75,90,95,99) in OAL,
+    # then five lines will be responsed, p50 is the first element of return value.
+    getMultiLinearsIntValues(metric: MetricCondition!, duration: Duration!): [IntValues!]!
     getThermodynamic(metric: MetricCondition!, duration: Duration!): Thermodynamic
 }