def get_part(self, vertex_in, vertices_border):
vertices_new = set(self.neighbors[vertex_in])<EOL>vertices_part = set([vertex_in])<EOL>while len(vertices_new) > <NUM_LIT:0>:<EOL><INDENT>pivot = vertices_new.pop()<EOL>if pivot in vertices_border:<EOL><INDENT>continue<EOL><DEDENT>vertices_part.add(pivot)<EOL>pivot_neighbors = set(self.neighbors[pivot])<EOL>pivot_neighbors -= vertices_part<EOL>vertices_new |= pivot_neighbors<EOL><DEDENT>return vertices_part<EOL>
List all vertices that are connected to vertex_in, but are not
           included in or 'behind' vertices_border.