question: public NexusBlock findBlockName ( String blockName ) { if ( blockName . equalsIgnoreCase ( ASSUMPTIONS_BLOCK . toString ( ) ) ) { return ASSUMPTIONS_BLOCK ; } else if ( blockName . equalsIgnoreCase ( SETS_BLOCK . toString ( ) ) ) { return SETS_BLOCK ; } else if ( blockName . equalsIgnoreCase ( PAUP_BLOCK . toString ( ) ) ) { return PAUP_BLOCK ; } else if ( blockName . equalsIgnoreCase ( MRBAYES_BLOCK . toString ( ) ) ) { return MRBAYES_BLOCK ; } else { return super . findBlockName ( blockName ) ; } }
target:  This function returns an enum class to specify what the block given by blockName is.