addin heading to convertPrrByKey2Csv() method

docs/SymptomsCausedByVaccines/js/PrrByKey2CsvConverter.js

@@ -1,12 +1,19 @@
 class PrrByKey2CsvConverter {
 
-    static convertPrrByKey2Csv({ prrByKey, keyColumn, prrColumn }) {
+    static convertPrrByKey2Csv(
-        return PrrByKey2CsvConverter.#convert2Csv(
+        {
-            {
+            heading,
-                prrByKey: PrrByKey2CsvConverter.#quoteKeys(prrByKey),
+            columns: { keyColumn, prrColumn },
-                keyColumn: PrrByKey2CsvConverter.#quote(keyColumn),
+            prrByKey
-                prrColumn: PrrByKey2CsvConverter.#quote(prrColumn)
+        }
-            });
+    ) {
+        return heading + '\n\n' +
+            PrrByKey2CsvConverter.#convert2Csv(
+                {
+                    prrByKey: PrrByKey2CsvConverter.#quoteKeys(prrByKey),
+                    keyColumn: PrrByKey2CsvConverter.#quote(keyColumn),
+                    prrColumn: PrrByKey2CsvConverter.#quote(prrColumn)
+                });
     }
 
     static #quoteKeys(prrByKey) {

docs/SymptomsCausedByVaccines/js/PrrByVaccineTableView.js

@@ -38,9 +38,12 @@ class PrrByVaccineTableView {
                     [
                         PrrByKey2CsvConverter.convertPrrByKey2Csv(
                             {
-                                prrByKey: this.#prrByVaccine,
+                                heading: '# Symptom: ' + this.#symptom,
-                                keyColumn: 'Vaccine',
+                                columns: {
-                                prrColumn: 'Proportional Reporting Ratio'
+                                    keyColumn: 'Vaccine',
+                                    prrColumn: 'Proportional Reporting Ratio'
+                                },
+                                prrByKey: this.#prrByVaccine
                             })
                     ],
                     { type: 'text/csv' })),

test/SymptomsCausedByVaccines/PrrByKey2CsvConverterTest.js

@@ -10,14 +10,19 @@ QUnit.module('PrrByKey2CsvConverterTest', function () {
         // When
         const csv = PrrByKey2CsvConverter.convertPrrByKey2Csv(
             {
-                prrByKey: prrByKey,
+                heading: '# Symptom: Acute hepatitis C',
-                keyColumn: 'Vaccine',
+                columns: {
-                prrColumn: 'Proportional Reporting Ratio'
+                    keyColumn: 'Vaccine',
+                    prrColumn: 'Proportional Reporting Ratio'
+                },
+                prrByKey: prrByKey
             });
 
         // Then
         const csvExpected =
-            `"Vaccine","Proportional Reporting Ratio"
+            `# Symptom: Acute hepatitis C
+
+"Vaccine","Proportional Reporting Ratio"
 "MM,R",26.17432376240791
 "VARCEL",10.549534724816644`;
         assert.equal(csv, csvExpected);