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The above function should load a text file from the disk, and return the number or characters in it.
Your test should specify the input the file name including its path, and the number of characters expected be in the file.
Assert on the actual file length (number of characters in the file) against the expected file length (number of characters read from the file)
In the production class we suggest you use something like File.readLinesreadAllLines()
Once you have completed the above test and production code, think about this question
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