Only valid when type: File or is an array of items: File.
If true, the file (or each file in the array) must be a UTF-8
text file 64 KiB or smaller, and the implementation must read
the entire contents of the file (or file array) and place it
in the contents field of the File object for use by
expressions. If the size of the file is greater than 64 KiB,
the implementation must raise a fatal error.
Only valid when type: File or is an array of items: File. If true, the file (or each file in the array) must be a UTF-8 text file 64 KiB or smaller, and the implementation must read the entire contents of the file (or file array) and place it in the contents field of the File object for use by expressions. If the size of the file is greater than 64 KiB, the implementation must raise a fatal error.