docs: def get_top_coins(tsym, limit=20):
  	"""Get top coins by 24 hour trading volume value in the requested currency.
  	
  	Args:
  		tsym: TO symbol.
  		limit: Number of results. Default value returns top 20 coins.
  	
  	Returns:
  		Function returns a list containing a dictionary for each result:
  
  		[{'SUPPLY': ..., 'SYMBOL': ..., 'VOLUME24HOURTO': ...}, 
  		 {...}, 
  		 ...]
  
  		The list is ordered based on the volume of the TO currency starting with 
  		the highest value.
  	"""
  	
  	# load data
  	url = build_url('volumes', tsym=tsym, limit=limit)
  	data = load_data(url)
  
  	return data['Data']