Returns a query string representation of a caplin a LogicalFilterExpression in a standard name/value pair format e.g. subject=/FI/123&start=12/10/2007

This method can only be used if all module:ct-grid/filter/LogicalFilterExpressions within the query use the module:ct-grid/filter/LogicalFilterExpression.Operator.AND logical operator and all module:ct-grid/filter/FieldFilterExpressions within the query use the module:ct-grid/filter/FieldFilterExpression.Operator.EQUAL operator. For this reason, it is best used with a module:ct-grid/filter/QueryFilterExpression which will enforce these rules for you.