code: def massi(high, low, fast=None, slow=None, offset=None, **kwargs):
      """Indicator: Mass Index (MASSI)"""
      # Validate arguments
      fast = int(fast) if fast and fast > 0 else 9
      slow = int(slow) if slow and slow > 0 else 25
      if slow < fast:
          fast, slow = slow, fast
      _length = max(fast, slow)
      high = verify_series(high, _length)
      low = verify_series(low, _length)
      offset = get_offset(offset)
      if "length" in kwargs:
          kwargs.pop("length")
  
      if high is None or low is None:
          return
  
      # Calculate Result
      high_low_range = non_zero_range(high, low)
      hl_ema1 = ema(close=high_low_range, length=fast, **kwargs)
      hl_ema2 = ema(close=hl_ema1, length=fast, **kwargs)
  
      hl_ratio = hl_ema1 / hl_ema2
      massi = hl_ratio.rolling(slow, min_periods=slow).sum()
  
      # Offset
      if offset != 0:
          massi = massi.shift(offset)
  
      # Handle fills
      if "fillna" in kwargs:
          massi.fillna(kwargs["fillna"], inplace=True)
      if "fill_method" in kwargs:
          massi.fillna(method=kwargs["fill_method"], inplace=True)
  
      # Name and Categorize it
      massi.name = f"MASSI_{fast}_{slow}"
      massi.category = "volatility"
  
      return massi
  
label_desc: Use image node_id 1 for calling a global function with example usage: massi(high, low, fast, slow, offset) and returns: massi