added examples

src/measurements/examples.js

@@ -345,6 +345,68 @@ basicContainer.getTypes().forEach(type => {
   }
 });
 
+// ---------------------------------------------------------------------------
+// --- Child Aggregation -----------------------------------------------------
+// ---------------------------------------------------------------------------
+
+// ====================================
+// AGGREGATION WITH CHILD SERIES (sum)
+// ====================================
+console.log();
+console.log('--- Example X: Aggregation with sum() and child series ---');
+
+// Container where flow is stored internally in m3/h
+const aggContainer = new MeasurementContainer({
+  windowSize: 10,
+  defaultUnits: {
+    flow: 'm3/h',
+  },
+});
+
+// Two pumps both feeding the same inlet position
+aggContainer
+  .child('pumpA')
+  .type('flow')
+  .variant('measured')
+  .position('inlet')
+  .value(10, Date.now(), 'm3/h'); // 10 m3/h
+
+aggContainer
+  .child('pumpB')
+  .type('flow')
+  .variant('measured')
+  .position('inlet')
+  .value(15, Date.now(), 'm3/h'); // 15 m3/h
+
+// Another position, e.g. outlet, also with two pumps
+aggContainer
+  .child('pumpA')
+  .type('flow')
+  .variant('measured')
+  .position('outlet')
+  .value(8, Date.now(), 'm3/h'); // 8 m3/h
+
+aggContainer
+  .child('pumpB')
+  .type('flow')
+  .variant('measured')
+  .position('outlet')
+  .value(11, Date.now(), 'm3/h'); // 11 m3/h
+
+
+// 1) Sum only inlet position (children pumpA + pumpB)
+const inletTotal = aggContainer.sum('flow', 'measured', ['inlet']);
+console.log(`Total inlet flow: ${inletTotal} m3/h (expected 25 m3/h)`);
+
+// 2) Sum inlet + outlet positions together
+const totalAll = aggContainer.sum('flow', 'measured', ['inlet', 'outlet']);
+console.log(`Total inlet+outlet flow: ${totalAll} m3/h (expected 44 m3/h)`);
+
+// 3) Same sum but explicitly ask for a target unit (e.g. l/s)
+//    This will use convertModule(...) internally.
+//    If conversion is not supported, it will fall back to the raw value.
+const totalAllLps = aggContainer.sum('flow', 'measured', ['inlet', 'outlet'], 'l/s');
+console.log(`Total inlet+outlet flow in l/s: ${totalAllLps} l/s (converted from m3/h)\n`);
 
 
 console.log('\n✅ All examples complete!\n');