code: private List<GroovyExpression> expandOrs(GroovyExpression expr, OptimizationContext context) {
  
          if (GremlinQueryOptimizer.isOrExpression(expr)) {
              return expandOrFunction(expr, context);
          }
          return processOtherExpression(expr, context);
      }
docs: Recursively traverses the given expression, expanding or expressions
  wherever they are found.
  
  @param expr
  @param context
  @return expressions that should be unioned together to get the query result