code: function getSymmetricDomain(domain, values) {
    const processedData = sortedUniq(values.sort((a, b) => a - b));
    const step = processedData[1] - processedData[0];
    return [domain[0], domain[1] + step];
  }
docs: Returns a symmetrically padded domain for polar charts
  @param {Array} domain: the original domain
  @param {Array} values: a flat array of values corresponding to either tickValues, or data values
  for a given dimension i.e. only x values.
  @returns {Array} the symmetric domain