When objectSpec is null, we retrieve objectMetadata to create a new objectSpec. This process involves calculating a list of parts using the divide method, which takes offset and length as inputs. If forExternalUse is false and length is 0, we utilize meta.getContentLength() to get the metadata length, which helps in generating the list of parts for creating the objectSpec
When objectSpec is null, we retrieve objectMetadata to create a new objectSpec. This process involves calculating a list of parts using the divide method, which takes offset and length as inputs. If forExternalUse is false and length is 0, we utilize meta.getContentLength() to get the metadata length, which helps in generating the list of parts for creating the objectSpec