Clean up exception docs and use statements

src/Operation/Aggregate.php

@@ -157,6 +157,7 @@ class Aggregate implements Executable
      * @see Executable::execute()
      * @param Server $server
      * @return Traversable
+     * @throws UnexpectedValueException if the command response was malformed
      */
     public function execute(Server $server)
     {

src/Operation/Count.php

@@ -102,6 +102,7 @@ class Count implements Executable
      * @see Executable::execute()
      * @param Server $server
      * @return integer
+     * @throws UnexpectedValueException if the command response was malformed
      */
     public function execute(Server $server)
     {

src/Operation/Distinct.php

@@ -79,6 +79,7 @@ class Distinct implements Executable
      * @see Executable::execute()
      * @param Server $server
      * @return mixed[]
+     * @throws UnexpectedValueException if the command response was malformed
      */
     public function execute(Server $server)
     {

src/Operation/Find.php

@@ -7,8 +7,6 @@ use MongoDB\Driver\ReadConcern;
 use MongoDB\Driver\ReadPreference;
 use MongoDB\Driver\Server;
 use MongoDB\Exception\InvalidArgumentException;
-use MongoDB\Exception\RuntimeException;
-use MongoDB\Exception\UnexpectedValueException;
 
 /**
  * Operation for the find command.

src/Operation/FindAndModify.php

@@ -130,6 +130,7 @@ class FindAndModify implements Executable
      * @see Executable::execute()
      * @param Server $server
      * @return object|null
+     * @throws UnexpectedValueException if the command response was malformed
      */
     public function execute(Server $server)
     {

src/Operation/ListCollections.php

@@ -5,7 +5,6 @@ namespace MongoDB\Operation;
 use MongoDB\Driver\Command;
 use MongoDB\Driver\Query;
 use MongoDB\Driver\Server;
-use MongoDB\Exception\RuntimeException;
 use MongoDB\Exception\InvalidArgumentException;
 use MongoDB\Model\CollectionInfoCommandIterator;
 use MongoDB\Model\CollectionInfoIterator;

src/Operation/ListDatabases.php

@@ -46,6 +46,7 @@ class ListDatabases implements Executable
      * @see Executable::execute()
      * @param Server $server
      * @return DatabaseInfoIterator
+     * @throws UnexpectedValueException if the command response was malformed
      */
     public function execute(Server $server)
     {