code: protected Object getQueryParameters() throws ActivityException {
          try {
              String paramVar = getAttributeValueSmart(PARAM_VAR);
              if (paramVar == null)
                  return null;
              return this.getVariableValue(paramVar);
          }
          catch (Exception ex) {
              throw new ActivityException(ex.getMessage(), ex);
          }
      }
docs: The method returns parameter values to use in the query.
  The default implementation returns the value of the defined parameters variable,
  which can be one of the following types:
  <ul>
  <li>java.lang.String</li>
  <li>java.lang.Integer</li>
  <li>java.lang.Long</li>
  <li>java.util.Date</li>
  <li>java.lang.String[]</li>
  <li>java.lang.Integer[]</li>
  <li>java.lang.Long[]</li>
  <li>java.lang.Object (as long as its value is one of the supported types, or an Array of supported types)</li>
  <li>null (no parameters)</li>
  </ul>
  
  If no parameterVariable is set, this behaves the same as if the variable value is null (no parameters).
  Returns an Object or an array of Objects constructed from the parameters.