compressedData = compressCsvToJson.compressData(sampleData, [
{ key: "oa21cd", colType: "interned_string" },
{ key: "lsoa21cd", colType: "string" },
{ key: "msoa21cd", colType: "string" },
{ key: "ltla21cd", colType: "string" },
{ key: "lng", colType: 10000 },
{ key: "lat", colType: 10000 },
{ key: "population", colType: "int" }
])