core/src/main/java/com/twitter/elephantbird/util/ThriftToDynamicProto.java
public FieldDescriptor getFieldDescriptor(Class<? extends TBase<?, ?>> thriftClass,
                                            String fieldName) {
    checkState(thriftClass);
    Descriptors.Descriptor descriptor = getBuilder(thriftClass).getDescriptorForType();
    return descriptor.findFieldByName(fieldName);
  }
public FieldDescriptor getFieldDescriptor(Class<? extends TBase<?, ?>> thriftClass,
                                            String fieldName) {
    checkState(thriftClass);
    Descriptors.Descriptor descriptor = getBuilder(thriftClass).getDescriptorForType();
    return descriptor.findFieldByName(fieldName);
  }
FieldDescriptor