How to use the gekko.Brain function in gekko

def build_brains():
    ## Explicit network solutions
 
    ## Implicit network solutions
    b2 = Brain(remote=False,bfgs=bfgs,explicit=explicit)
    
    #input layer
    b2.input_layer(4)
    
    #intermediate layers
    b2.layer(2,0,2,2)
    b2.layer(2,0,2,2)
    #output layer
    b2.output_layer(1)
    
    # extra options for this problem
    for l in b2._weights:
        for f in l:
            f.DMAX= dmax
    
    return b2