OptionalsourceSource identifier for error reporting (e.g., filename, description).
This option allows you to specify a human-readable identifier for the CSV source that will be included in error messages. This is particularly useful when parsing multiple files or streams to help identify which source caused an error.
Security Note: Do not include sensitive information (API keys, tokens, full URLs) in this field as it may be exposed in error messages and logs.
Source identifier option for error reporting.