def find_neighbors(vertex_array)
      vertex_array_check(vertex_array)
      neighbors = []
      vertex_array.each do |vertex|
        @faces.each do |face|
          neighbors << face if face.vertices.include?(vertex)
        end
      end
      neighbors.uniq
    end
def find_neighbors(vertex_array)
      vertex_array_check(vertex_array)
      neighbors = []
      vertex_array.each do |vertex|
        @faces.each do |face|
          neighbors << face if face.vertices.include?(vertex)
        end
      end
      neighbors.uniq
    end
Return all faces containing the given vertices