code: @Override
      public GetSlotTypeVersionsResult getSlotTypeVersions(GetSlotTypeVersionsRequest request) {
          request = beforeClientExecution(request);
          return executeGetSlotTypeVersions(request);
      }
docs: <p>
  Gets information about all versions of a slot type.
  </p>
  <p>
  The <code>GetSlotTypeVersions</code> operation returns a <code>SlotTypeMetadata</code> object for each version of
  a slot type. For example, if a slot type has three numbered versions, the <code>GetSlotTypeVersions</code>
  operation returns four <code>SlotTypeMetadata</code> objects in the response, one for each numbered version and
  one for the <code>$LATEST</code> version.
  </p>
  <p>
  The <code>GetSlotTypeVersions</code> operation always returns at least one version, the <code>$LATEST</code>
  version.
  </p>
  <p>
  This operation requires permissions for the <code>lex:GetSlotTypeVersions</code> action.
  </p>
  
  @param getSlotTypeVersionsRequest
  @return Result of the GetSlotTypeVersions operation returned by the service.
  @throws NotFoundException
  The resource specified in the request was not found. Check the resource and try again.
  @throws LimitExceededException
  The request exceeded a limit. Try your request again.
  @throws InternalFailureException
  An internal Amazon Lex error occurred. Try your request again.
  @throws BadRequestException
  The request is not well formed. For example, a value is invalid or a required field is missing. Check the
  field values, and try again.
  @sample AmazonLexModelBuilding.GetSlotTypeVersions
  @see <a href="http://docs.aws.amazon.com/goto/WebAPI/lex-models-2017-04-19/GetSlotTypeVersions" target="_top">AWS
  API Documentation</a>