from typing import TypeVar, Generic

T = TypeVar( 'T' )

class Tree( Generic[ T ] ):
    def __init__( self, key ) -> None:
        self.left  : Optional[ Tree ] = None
        self.right : Optional[ Tree ] = None
        self.key = key

    async def search( self, key, suspend ) -> bool:
        await suspend( self.key )
        r = False

        if key == self.key:
            r = True
        if key < self.key and self.left is not None:
            r = await self.left.search( key, suspend )
        if key > self.key and self.right is not None:
            r = await self.right.search( key, suspend )

        return r