{{tag>Programmers_Reference Methods IFunctionLibrary_Interface}}

======getRequiredFactPatterns (String, Collection)======

**Interface:** [[3500:0500:0510|IFunctionLibrary]]
<code java>public HashSet getRequiredFactPatterns (String functionName, Collection parameters)</code>

=====Parameters=====
|''functionName''|the name of the function in the library the return type of which is required.|
|''parameters''|the parameters of the function specified as a collection of the ''IArithmeticNode'' objects. |

=====Returns=====
This method should have no implementation and return ''null''.