Return a new Runnable that maps a list of inputs to a list of outputs.
Calls invoke with each input.
Example:
from langchain_core.runnables import RunnableLambda
def _lambda(x: int) -> int:
return x + 1
runnable = RunnableLambda(_lambda)
print(runnable.map().invoke([1, 2, 3])) # [2, 3, 4]