old_contents: SEG_NON_POSITIVE_MESSAGE = "The segment size must be a positive integer"
  OVERLAP_LARGE_MESSAGE = "The segment size must be greater than " \
      "the overlap of words between chunks"
  PROP_NEGATIVE_MESSAGE = "The proportional size of the last segment must be " \
      "zero or greater"
  OVERLAP_NEGATIVE_MESSAGE = "The overlap between chunks must be zero or greater"
  NON_POSITIVE_NUM_MESSAGE = "the segment size should larger be positive"
  NEG_NUM_MESSAGE = "the overlap or last segment proportion should " \
      "not be negative"
  LARGER_CHUNK_SIZE_MESSAGE = "the segment size should be larger " \
      "than the overlap size"
  
new_contents: SEG_NON_POSITIVE_MESSAGE = "The segment size must be a positive integer"
  OVERLAP_LARGE_MESSAGE = "The segment size must be greater than " \
      "the overlap of words between chunks"
  PROP_NEGATIVE_MESSAGE = "The proportional size of the last segment must be " \
      "zero or greater"
  OVERLAP_NEGATIVE_MESSAGE = "The overlap between chunks must be zero or greater"
  NON_POSITIVE_NUM_MESSAGE = "the segment size should larger be positive"
  NEG_NUM_MESSAGE = "the overlap or last segment proportion should " \
      "not be negative"
  LARGER_CHUNK_SIZE_MESSAGE = "the segment size should be larger " \
      "than the overlap size"
  EMPTY_INPUT_MESSAGE = "the input must contain desired information"
  
subject: Add error message