Groovy StreamingMarkupBuilder output XML separator

I'm currently using in my groovy script the StreamingMarkupBuilder to produce my output XMl. Works all pretty well but when I have multiple elements with the same name in the source message, do I have an option to add separatos?

<Organisation>
   <Name>Name1</Name>
   <Name>Name2</Name>
   <Name>Name3</Name>
</Organisation>`

I use it in the following way:

builder.OrganisationName{
   NameFormatted Organisation.Name.toString() 
}

In my output I receive:

<NameFormatted>
   Name1Name2Name3
</NameFormatted>

I want to receveive the following - each element separated by blank or pre-defined separater

<NameFormatted>
  Name1 Name2 Name3
</NameFormatted>

Does anybody have a tip for me?

Thanks Marco

Please try in the following way:

import groovy.util.XmlSlurper
import groovy.xml.StreamingMarkupBuilder
import groovy.xml.XmlUtil

def slurped = new XmlSlurper().parseText('''<Organisation>
   <Name>Name1</Name>
   <Name>Name2</Name>
   <Name>Name3</Name>
</Organisation>''')

println slurped.Name

def builder = new StreamingMarkupBuilder()
def output = builder.bind {
    OrganisationName {
        NameFormatted slurped.Name.join(' ')
    }
}
println XmlUtil.serialize(output)

Other separators can also be passed to join instead of space.