review: Fix spelling and other documentation issues

Author: t2gran

application/src/main/java/org/opentripplanner/graph_builder/module/transfer/filter/MinMap.java

@@ -3,11 +3,10 @@
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.Map;
+import javax.annotation.Nullable;
 
 /**
- * A HashMap that has been extended to track the greatest or smallest value for each key. Note that
- * this does not change the meaning of the 'put' method. It adds two new methods that add the
- * min/max behavior. This class used to be inside SimpleIsochrone.
+ * Decorate a HashMap that to track the smallest value for each key.
  */
 class MinMap<K, V extends Comparable<V>> {
 
@@ -17,6 +16,7 @@ class MinMap<K, V extends Comparable<V>> {
    * Put the given key-value pair in the map if the map does not yet contain the key, or if the
    * value is less than the existing value for the same key.
    *
+   * @see Map#put(Object, Object) 
    * @return whether the key-value pair was inserted in the map.
    */
   boolean putMin(K key, V value) {
@@ -31,6 +31,7 @@ boolean putMin(K key, V value) {
   /**
    * @see Map#get(Object)
    */
+  @Nullable
   public V get(K key) {
     return map.get(key);
   }

application/src/test/java/org/opentripplanner/graph_builder/module/transfer/DirectTransferGeneratorTest.java

@@ -13,7 +13,7 @@
 
 /**
  * This test uses the following graph/network for testing the DirectTransfer generation. The
- * fokus is on the filtering of the transfers, not on testing that the NearBySearch return the
+ * focus is on the filtering of the transfers, not on testing that the NearBySearch return the
  * correct set of nearby stops.
  * <p>
  * <img src=DirectTransferGeneratorTest.drawio.png />