public Tag withKey(String key) {
        setKey(key);
        return this;
    }
<p>
The key of the tag. Tag keys are case sensitive. Each Amazon Keyspaces resource can only have up to one tag with
the same key. If you try to add an existing tag (same key), the existing tag value will be updated to the new
value.
</p>

@param key
       The key of the tag. Tag keys are case sensitive. Each Amazon Keyspaces resource can only have up to one
       tag with the same key. If you try to add an existing tag (same key), the existing tag value will be
       updated to the new value.
@return Returns a reference to this object so that method calls can be chained together.
aws-java-sdk-keyspaces/src/main/java/com/amazonaws/services/keyspaces/model/Tag.java