text: from ethereum import utils as u
  from plasma_core.constants import NULL_HASH
  from plasma_core.utils.merkle.fixed_merkle import FixedMerkle
  
  
  def get_empty_merkle_tree_hash(depth):
      zeroes_hash = NULL_HASH
      for _ in range(depth):
          zeroes_hash = u.sha3(zeroes_hash + zeroes_hash)
      return zeroes_hash
  
  
  def get_merkle_of_leaves(depth, leaves):
      return FixedMerkle(depth, leaves)
  
  
  def bytes_fill_left(inp, length):
      return bytes(length - len(inp)) + inp
  
  
  def get_deposit_hash(owner, token, value):
      return u.sha3(owner + token + b'\x00' * 31 + u.int_to_bytes(value))
  