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 segments must be zero or " \
                             "greater"
  NON_POSITIVE_SEGMENT_MESSAGE = "the segment size should be positive"
  NEG_OVERLAP_LAST_PROP_MESSAGE = "the overlap or last segment proportion" \
                                  "should not be negative"
  LARGER_SEG_SIZE_MESSAGE = "the segment size should be larger " \
      "than the overlap size"
  NON_NEGATIVE_INDEX_MESSAGE = "the index should be larger than or equal to zero"
  MATRIX_DIMENSION_UNEQUAL_MESSAGE = "the dimension of the matrix " \
      "should be equal"
  EMPTY_LIST_MESSAGE = "the list should not be empty"
  WINDOW_SIZE_LARGE_MESSAGE = "The window size must be less than or equal to" \
                              " the length of the given document"
  INVALID_CUTTING_TYPE_MESSAGE = "the cutting type should be letters, lines, " \
      "number, words or milestone"
  EMPTY_MILESTONE_MESSAGE = "the milestone should not be empty"
  
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 segments must be zero or " \
                             "greater"
  NON_POSITIVE_SEGMENT_MESSAGE = "the segment size should be positive"
  NEG_OVERLAP_LAST_PROP_MESSAGE = "the overlap or last segment proportion" \
                                  "should not be negative"
  LARGER_SEG_SIZE_MESSAGE = "the segment size should be larger " \
      "than the overlap size"
  NON_NEGATIVE_INDEX_MESSAGE = "the index should be larger than or equal to zero"
  MATRIX_DIMENSION_UNEQUAL_MESSAGE = "the dimension of the matrix " \
      "should be equal"
  EMPTY_LIST_MESSAGE = "the list should not be empty"
  WINDOW_SIZE_LARGE_MESSAGE = "The window size must be less than or equal to" \
                              " the length of the given document"
  INVALID_CUTTING_TYPE_MESSAGE = "the cutting type should be letters, lines, " \
      "number, words or milestone"
  EMPTY_MILESTONE_MESSAGE = "the milestone should not be empty"
  EMPTY_STRING_MESSAGE = "the string should not be empty"
  
subject: fix conflict in error message