human
Solve the following python programming problem given the following code:
@ classmethod 
def calculate_classpath(cls, targets) : 
    "Creates a consistent classpath and list of excludes for the passed targets.

    It also modifies the JarDependency objects' excludes to contain all the jars excluded by
    provides.

    :param iterable targets: List of targets to collect JarDependencies and excludes from.

    :returns: A pair of a list of JarDependencies, and a set of excludes to apply globally.
    " 
    jars = OrderedDict () 
    global_excludes = set () 
    provide_excludes = set () 
    targets_processed = set () 
    def add_jar(jar) : 
        coordinate = (jar.org, jar.name, jar.classifier) 
        existing = jars.get (coordinate) 
        jars [coordinate] = (jar if (not existing) else cls._resolve_conflict (existing = existing, proposed = jar)) 
def collect_jars(target) : 
        if isinstance (target, JarLibrary) : 
            for jar in target.jar_dependencies : 
                add_jar (jar) 
def collect_excludes(target) : 
        target_excludes = target.payload.get_field_value ('excludes') 
        if target_excludes : 
            global_excludes.update (target_excludes) 
def collect_provide_excludes(target) : 
        if (not target.is_exported) : 
            return 
logger.debug ('Automatically excluding jar {}.{}, which is provided by {}'.format (target.provides.org, target.provides.name, target)) 
        provide_excludes.add (Exclude (org = target.provides.org, name = target.provides.name)) 
def collect_elements(target) : 
        targets_processed.add (target) 
        collect_jars (target) 
        collect_excludes (target) 
        collect_provide_excludes (target) 
for target in targets : 
        target.walk (global_excludes, predicate = (lambda target : (target not in targets_processed))) 
if provide_excludes : 
        additional_excludes = tuple (provide_excludes) 
        new_jars = OrderedDict () 
        for (coordinate, jar) in jars.items () : 
            new_jars [coordinate] = jar.copy (excludes = (jar.excludes + additional_excludes))...

    
    

    Fix the buggy line: target.walk (global_excludes, predicate = (lambda target : (target not in targets_processed)))
assistant
#Here is Python code to fix the buggy line: target.

target.walk (def collect_elements(, predicate = (lambda target : (target not in targets_processed)))