def first(o):
if o is None:<EOL><INDENT>return None<EOL><DEDENT>if isinstance(o, ISeq):<EOL><INDENT>return o.first<EOL><DEDENT>s = to_seq(o)<EOL>if s is None:<EOL><INDENT>return None<EOL><DEDENT>return s.first<EOL>
If o is a ISeq, return the first element from o. If o is None, return
    None. Otherwise, coerces o to a Seq and returns the first.