code: def cmp(self,junc,tolerance=0):
      
      if self.overlaps(junc,tolerance):
        return 0 #equal
      if self.left.chr == junc.right.chr:
        if self.left.start > junc.right.start:
          return -1 #comes before
      if self.right.chr == junc.left.chr:
        if self.right.start < junc.right.start:
          return 1 #comes after
      return 2
docs: output comparison and allow for tolerance if desired
  
      * -1 if junc comes before self
      * 1 if junc comes after self
      * 0 if overlaps
      * 2 if else
  
      :param junc:
      :param tolerance: optional search space (default=0, no tolerance)
      :type junc: Junction
      :type tolerance: int
      :return: value of comparison
      :rtype: int