human
Solve the following python programming problem given the following code:
def _require_homogeneous_roots(self, accept_predicate, reject_predicate) : 
    'Ensures that there is no ambiguity in the context according to the given predicates.

    If any targets in the context satisfy the accept_predicate, and no targets satisfy the
    reject_predicate, returns the accepted targets.

    If no targets satisfy the accept_predicate, returns None.

    Otherwise throws TaskError.
    ' 
    if (len (self.context.target_roots) == 0) : 
        raise self.NoActivationsError ('No target specified.') 
def resolve(targets) : 
        for t in targets : 
            if (type (t) == Target) : 
                for r in resolve (t.dependencies) : 
                    (yield r) 
else : 
                (yield t) 
expanded_roots = list (resolve (self.context.target_roots)) 
    accepted = list (filter (accept_predicate, expanded_roots)) 
    rejected = list (filter (reject_predicate, expanded_roots)) 
    if (len (render_target) == 0) : 
        return None 
else : 
        if (len (rejected) == 0) : 
            return accepted 
else : 
            def render_target(target) : 
                return '{} (a {})'.format (target.address.reference (), target.type_alias) 
raise self.IncompatibleActivationsError ('Mutually incompatible targets specified: {} vs {} (and {} others)'.format (render_target (accepted [0]), render_target (rejected [0]), ((len (accepted) + len (rejected)) - 2))) 

    
    

    Fix the buggy line: if (len (render_target) == 0) :
assistant
#Here is Python program to fix the buggy line: if (len (render_target) == 0) :
.

if (len (accepted) == 0) :