Removing an agent's association to a table-reading function can be done
with remove_read_fn(). This may be good idea when instead relying on the
direct association of a data table (settable in create_agent()'s tbl
argument or with set_tbl()), where the table-reading function is no longer
relevant.
remove_read_fn(agent)An agent object of class ptblank_agent that is created with
create_agent().