message: cannot destructure a null--adding guard
diff: @@ -185,7 +185,10 @@ class EthereumBuffer {
  let methodAbiEntry = contractDefinition["abi"].find(item => item.type === 'function' &&
  item.constant &&
  item.name === methodName);
  - let { isMapping, fields } = fieldTypeFor(contractName, methodAbiEntry);
  + let fieldInfo = fieldTypeFor(contractName, methodAbiEntry);
  + if (!fieldInfo) { continue; }
  +
  + let { isMapping, fields } = fieldInfo;
  if (!isMapping || !fields.length) { continue; }
  let model = {
  