1. A method in a computing device with a processor and a memory for generating wrappers for hierarchically organized documents, each document having a document tree with nodes, the method comprising: generating by the processor, for each of a plurality of clusters of documents, a wrapper by repeating the following until all the documents have been selected: selecting a document that has not yet been selected for creation of a wrapper tree having nodes; creating the wrapper tree for the document tree of the selected document; for each document whose distance from its document tree to the wrapper tree is within a threshold distance, selecting the document; and adjusting the wrapper tree based on the document tree of the selected document; and establishing the wrapper for the documents selected for creation and adjustment of the wrapper tree based on the adjusted wrapper tree wherein a wrapper tree is created and adjusted for each cluster of documents whose document trees are within a threshold distance of the wrapper tree at the time of selection of the document, and wherein distance is represented by the following equation: Ψ ⁡ ( T w , T d ) = ( C w ⁡ ( T w , T d ) W ⁡ ( T w ) + C d ⁡ ( T w , T d ) W ⁡ ( T w ) ) / 2 ( 3 ) where Ψ(T w ,T d ) represents the distance between wrapper tree T w and document tree T d , C w (T w ,T d ) represents count of nodes of the wrapper tree T w that do not match document nodes of document tree T d , C d (T w ,T d ) represents count of nodes of document tree T d that do not match wrapper nodes of the wrapper tree T w , and W(T w ) represents a weight of wrapper tree T w .