function evaluateNestedExpression(expression, call) {
    // Remove the calc part from nested expressions to ensure
    // better browser compatibility
    expression = expression.replace(/((?:\-[a-z]+\-)?calc)/g, "")
    var evaluatedPart = ""
    var nonEvaluatedPart = expression
    var matches
    while ((matches = NESTED_CALC_RE.exec(nonEvaluatedPart))) {
      if (matches[0].index > 0) {
        evaluatedPart += nonEvaluatedPart.substring(0, matches[0].index)
      }

      var balancedExpr = balanced("(", ")", nonEvaluatedPart.substring([0].index))
      if (balancedExpr.body === "") {
        throw new Error("'" + expression + "' must contain a non-whitespace string")
      }

      var evaluated = evaluateExpression(balancedExpr.body, "", call)

      evaluatedPart += balancedExpr.pre + evaluated
      nonEvaluatedPart = balancedExpr.post
    }

    return evaluatedPart + nonEvaluatedPart
  }
Evaluates nested expressions

@param {String} expression
@returns {String}