ched.
  count: The max number of pattern occurrences to be replaced. Must be
    non-negative. If omitted or zero, all occurrences will be replaces.
  ignorecase: Whether to perform case-insensitive matching.

Returns:
  A new string with the replacements applied.

Example:
  `table(field.sub(" there", ""))`:::
  If the field string is "hey there" it will be displayed as "hey".
)	r[