Combines two patterns into a new pattern that is returned.
<p>The full algorithm used for combining the two pattern depends on the underlying implementation.
@param pattern1 the first pattern
@param pattern2 the second pattern
@return the combination of the two patterns
@throws IllegalArgumentException when the two patterns cannot be combined
Combines two patterns into a new pattern that is returned. <p>The full algorithm used for combining the two pattern depends on the underlying implementation. @param pattern1 the first pattern @param pattern2 the second pattern @return the combination of the two patterns @throws IllegalArgumentException when the two patterns cannot be combined