input: Write a function to create an object-oriented structure to solve a maze in Python. The function should initialize a Maze object with dimensions n and m, and provide a method to solve the maze. The solve_maze method should use a recursive approach to find the shortest path from the start (0, 0) to the end (n-1, m-1) if it exists, and return the path as a list of values representing the steps. If no path is found, the method should return an empty list.
  
  class Maze:
      def __init__(self, n, m):
          self._n, self._m = n, m
          self._grid = [[None] * m for _ in range(n)]
  
      def solve_maze(self):
          result, found = [], False
          start, end = (0, 0), (self._n-1, self._m-1)
  
          for i in range(self._n):
              for j in range(self._m):
                  if self._grid[i][j] == 1:
                      value = 0
                      self._find_omega(i, j, value, result, start, end,
                                       found)
                      return result
  
      def _find_omega(self, i, j, value,
                      result, start, end, found):
          rowNbr, colNbr = [-1, 0, 0, 1], [0, -1, 1, 0]
  
          if (i, j) == end:
              found = True
              result.append(value)
              return
  
          if found == True:
              return
  
          self._grid[i][j] = 0
          for k in range(4):
              if self._on_board(i + rowNbr[k], j + colNbr[k]):
                  self._find_omega(i + rowNbr[k], j + colNbr[k],
                                   value + 1, result,
                                   start, end, found)
  
      def _on_board(self, i, j):
          return 0 <= i < self._n and 0 <= j < self._m and self._grid[i][j] == 1
  
  assert Maze(5, 5).solve_maze() == [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
  assert Maze(3, 3).solve_maze() == [0, 1, 2, 3, 4, 5]
  assert Maze(4, 4).solve_maze() == [0, 1, 2, 3, 4, 5, 6, 7]
  assert Maze(2, 2).solve_maze() == [0, 1, 2]
  assert Maze(1, 1).solve_maze() == [0]
output: def solve_maze(self):
      result, found = [], False
      start, end = (0, 0), (self._n-1, self._m-1)
  
      for i in range(self._n):
          for j in range(self._m):
              if self._grid[i][j] == 1:
                  value = 0
                  self._find_omega(i, j, value, result, start, end, found)
                  return result
  
  def _find_omega(self, i, j, value, result, start, end, found):
      rowNbr, colNbr = [-1, 0, 0, 1], [0, -1, 1, 0]
  
      if (i, j) == end:
          found = True
          result.append(value)
          return
  
      if found == True:
          return
  
      self._grid[i][j] = 0
      for k in range(4):
          if self._on_board(i + rowNbr[k], j + colNbr[k]):
              self._find_omega(i + rowNbr[k], j + colNbr[k], value + 1, result, start, end, found)
  
  def _on_board(self, i, j):
      return 0 <= i < self._n and 0 <= j < self._m and self._grid[i][j] == 1