Compose pipe model

If I have two models are just composable (one's output is another's input), I hope not to write another model to run them but just specify a so-called "running pipe".

For example,

model B: input: Token, output: B_DTO
model A: input B_DTO, output A_DTO

The running pipe's schema could be 

```
{
"run": "A",
"deps":
{
"A":{"model": "B"),
"B": {"input": {"address": "0x...."}}
}
```