code: function (chain, type) {
      const oThis = this;
      if (oThis.valueChain === chain) {
        if (oThis.typeRPC === type) {
          return require(rootPrefix + '/lib/web3/providers/value_rpc');
        } else if (oThis.typeWS === type) {
          return require(rootPrefix + '/lib/web3/providers/value_ws');
        }
      } else if (oThis.utilityChain === chain) {
        if (oThis.typeRPC === type) {
          return require(rootPrefix + '/lib/web3/providers/utility_rpc');
        } else if (oThis.typeWS === type) {
          return require(rootPrefix + '/lib/web3/providers/utility_ws');
        }
      }
      return null;
    }
docs: Perform
  
  @param {string} chain - chain name - value / utility
  @param {string} type - provider type - ws / rpc
  
  @return {web3Provider}