fix: use assertthrows and update docs

Author: SethFalco

src/main/java/org/apache/commons/csv/CSVFormat.java

@@ -1463,10 +1463,10 @@ public boolean getAllowDuplicateHeaderNames() {
     }
 
     /**
-     * Returns how duplicate headers are handled.
+     * Gets how duplicate headers are handled.
      *
      * @return if duplicate header values are allowed, allowed conditionally, or disallowed.
-     * @since 1.9
+     * @since 1.9.0
      */
     public DuplicateHeaderMode getDuplicateHeaderMode() {
         return duplicateHeaderMode;

src/main/java/org/apache/commons/csv/CSVParser.java

@@ -17,6 +17,8 @@
 
 package org.apache.commons.csv;
 
+import static org.apache.commons.csv.Token.Type.TOKEN;
+
 import java.io.Closeable;
 import java.io.File;
 import java.io.IOException;
@@ -43,8 +45,6 @@
 import java.util.stream.Stream;
 import java.util.stream.StreamSupport;
 
-import static org.apache.commons.csv.Token.Type.TOKEN;
-
 /**
  * Parses CSV files according to the specified format.
  *

src/main/java/org/apache/commons/csv/DuplicateHeaderMode.java

@@ -21,23 +21,22 @@
  * Determines how duplicate header fields should be handled
  * if {@link CSVFormat#withHeader(String...)} is not null.
  *
- * @since 1.9
+ * @since 1.9.0
  */
 public enum DuplicateHeaderMode {
 
     /**
-     * Allows all duplicate headings.
+     * Allows all duplicate headers.
      */
     ALLOW_ALL,
 
     /**
-     * Allows duplicate headings only if they're empty
-     * strings or null.
+     * Allows duplicate headers only if they're empty strings or null.
      */
     ALLOW_EMPTY,
 
     /**
-     * Disallows duplicate headings entirely.
+     * Disallows duplicate headers entirely.
      */
     DISALLOW
 }

src/test/java/org/apache/commons/csv/issues/JiraCsv264Test.java

@@ -19,20 +19,21 @@
 
 import org.apache.commons.csv.CSVFormat;
 import org.apache.commons.csv.DuplicateHeaderMode;
-import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
 import java.io.IOException;
 import java.io.StringReader;
 
 /**
- * When {@link CSVFormat#withHeader(String...)} is not null;
- * duplicate headers with empty strings should not be allowed.
+ * When {@link CSVFormat#withHeader(String...)} is not null; duplicate headers
+ * with empty strings should not be allowed.
  *
- * @see <a href="https://issues.apache.org/jira/projects/CSV/issues/CSV-264?filter=allopenissues">Jira Ticker</a>
+ * @see <a href="https://issues.apache.org/jira/browse/CSV-264">Jira Ticker</a>
  */
 public class JiraCsv264Test {
-  
+
     private static final String CSV_STRING = "\"\",\"B\",\"\"\n" +
                                              "\"1\",\"2\",\"3\"\n" +
                                              "\"4\",\"5\",\"6\"";
@@ -54,12 +55,7 @@ public void testJiraCsv264() throws IOException {
             .build();
 
         try (StringReader reader = new StringReader(CSV_STRING)) {
-            try {
-                csvFormat.parse(reader);
-                Assertions.fail("This shouldn't parse the CSV string successfully.");
-            } catch (IllegalArgumentException ex) {
-                // Test is successful!
-            }
+            assertThrows(IllegalArgumentException.class, () -> csvFormat.parse(reader));
         }
     }
 
@@ -87,12 +83,7 @@ public void testJiraCsv264WithGapDisallow() throws IOException {
             .build();
 
         try (StringReader reader = new StringReader(CSV_STRING_GAP)) {
-            try {
-                csvFormat.parse(reader);
-                Assertions.fail("This shouldn't parse the CSV string successfully.");
-            } catch (IllegalArgumentException ex) {
-                // Test is successful!
-            }
+            assertThrows(IllegalArgumentException.class, () -> csvFormat.parse(reader));
         }
     }
 }