public void setGameProperties(java.util.Collection<GameProperty> gameProperties) {
        if (gameProperties == null) {
            this.gameProperties = null;
            return;
        }

        this.gameProperties = new java.util.ArrayList<GameProperty>(gameProperties);
    }
<p>
A set of key-value pairs that can store custom data in a game session. For example:
<code>{"Key": "difficulty", "Value": "novice"}</code>. You can use this parameter to modify game properties in an
active game session. This action adds new properties and modifies existing properties. There is no way to delete
properties. For an example, see <a href=
"https://docs.aws.amazon.com/gamelift/latest/developerguide/gamelift-sdk-client-api.html#game-properties-update"
>Update the value of a game property</a>.
</p>

@param gameProperties
       A set of key-value pairs that can store custom data in a game session. For example:
       <code>{"Key": "difficulty", "Value": "novice"}</code>. You can use this parameter to modify game
       properties in an active game session. This action adds new properties and modifies existing properties.
       There is no way to delete properties. For an example, see <a href=
       "https://docs.aws.amazon.com/gamelift/latest/developerguide/gamelift-sdk-client-api.html#game-properties-update"
       >Update the value of a game property</a>.
aws-java-sdk-gamelift/src/main/java/com/amazonaws/services/gamelift/model/UpdateGameSessionRequest.java